Felix Ruehle coming to Wallaby Ranch

ATOS

Felix Ruehle|Malcolm Jones

Ben Herring <<ben>> writes:

Felix Ruehle is joining Wallaby Ranch and A-I-R USA in delivering 3 brand-spanking new ATOS gliders to Wallaby Ranch in Florida on June 8. There will be some informal clinics as well as lots of Q&A and storytelling including more information about the upcoming production of the ATOS Wing.

Pilots, both flex and rigid, are invited to come join Felix, Malcolm Jones, Fred Kaemerer and Ben Herring for a weekend filled with all-things ATOS.

The wire and the pulley

ATOS

Aeronautic Innovation Rühle & Co GmbH|Felix Ruehle|Jim Lamb

www.a-i-r.de

Felix Ruehle «felix» writes:

Please check the control cable on all ATOSes with the carbon control frames. We found cables that have not been checked.

Please check the cable close to the pulley before every flight. It is best to check before each flight and then during break down. Usually the cable shows wear first at the small keel pulley. It has to be replaced if there is even just one broken strand!

You can get a new control cable from A-I-R (or in USA from Jim Lamb).

A new replacement pulley will be soon available (in about three weeks).

Discuss "AIR Safety Notice" at the Oz Report forum   link»  

A.I.R. ATOS VR|Brett Hazlett|Bruce Barmakian|Chris Muller|Davis Straub|Dr. John "Jack" Glendening|Dustin Martin|Felix Ruehle|Flytec Championships 2005|Glen Volk|Jacques Bott|Jim Lamb|Johann Posch|Jon "Jonny" Durand jnr|Kevin Carter|Mike Barber|Nichele Roberto|Oleg Bondarchuk|Paris Williams|Phill Bloom|Robert Reisinger|Ron Gleason|Russell "Russ" Brown|weather

Wed, Apr 20 2005, 5:00:00 pm EDT

Under called on a great day, but that makes most happy.

Flytec Championship

Today's flight and rigid wing task

The day started with thick clouds covering the sky until mid morning. This made the pilots wary. I knew from the forecast that these clouds would go away and the day would be sunny.

Dr. Jack, using the RUC (Rapid Update Cycle) model, called for a day like any other here recently with lighter winds (5 mph) out of the southeast, and maybe a cloud or two unlike the previous days where we saw nothing but wispies. The National Weather Service mentioned cirrus again, as we've had for the last two days. But there was a fly in the ointment.

The FSL chart completely disagreed with the RUC model. It called for cunimbs,and strong lift (even though the local forecast showed no rain). The winds on the FSL chart also rotated ninety degrees from northeast on the ground to southeast at 6,000' cloud base. But we were seeing light southeast on the ground.

Given the conflict in the models, the task committee called for a task that was 20% longer than the day before hoping for a three hour task. The winds in the launch field were switchy with a few bad tows.

Later in the morning the cirrus began to disappear and it looked like it would clear off completely. The satellite also showed this with clearing to the west.

The cu's were forming nicely and thickly throughout the sky (give that one to the FSL model) and this was very inviting. The winds were light. Lots of pilots wanted to launch early so I had to wait a bit to get launched. The lift over the field was not that great and all the lift we found in the start circle was weak. Jim Lamb was pulled way north, found 700 fpm, unlike the rest of us, and climbed to cloudbase immediately. He had to come back and hang with the rest of us who worked less than 100 fpm to get to cloud base. The clouds looked great, but it felt like they were faking it. The lift was so weak we struggled to get to cloudbase at 5,200'.

We were five miles north of Quest at the edge of the start circle. The course line was to our west.  It was unclear what would happen at 1:45 the first start time. A few people headed out. I headed out then came back. More people headed out. I followed Robert Reisinger as he headed out, as my strategy for the day was to stick to Robert. Then he turned around and came back. Now there were only three of us left out of the main gaggle: Robert, Ron Gleason, and me.

We promptly fell down to 3,000' before we found 200 fpm (what luck) at the same spot we started with the original gaggle. As fifteen minutes slipped by we climbed back up to 4,800', all three of us very near each other in altitude. It looked like everyone else took the early start clock. We were feeling pretty darn smart.

Felix Ruehle, who was on top at 1:45, also turned around after going out a bit, but didn't find any lift and had to land back at Quest and relaunch fourteen minutes after the last start time. He would be on his own after that.

At 2 PM we headed off together spreading out to help each other find the lift. With the mostly weak lift that we'd experienced we were not expecting much out on the course. We quickly caught up with a couple of stragglers from the earlier clock. 

The lift wasn't all that great. I was gliding and climbing with Robert, but Ron couldn't glide with us. Something is wrong with his setup. Robert and Ron will swap gliders in the morning and do some side by side comparisons to get to the root of the problem.

I had no worries staying with the Robert all the way to the turnpoint as we caught one pilot after another. The lift wasn't strong at all, but we were moving quickly from thermal to thermal.

Finally, after the turnpoint 34 miles north northwest of Quest at Savana air strip, I found the first good core and climbed from 2,600' at 600 fpm with Robert twenty feet over my head. I lost track of him in this thermal and I was on my own to get back home. Ron Gleason took a different line and met us there.

A few miles out from the turnpoint there was a cloud street paralleling the Florida Turnpike heading back toward Groveland. I got under it, climbed up fast and road that sucker all the way home. Johann Posch and Ron Gleason as well as a few others followed behind.

After I landed I found out that we weren't the only ones to take the later clock. The others were hiding more on the course line to our west. Robert apologized for not finding better lift. The others had a much better run down to the turnpoint than we did. Robert would pick this day to go slower (well, it wasn't that bad).

Rigids today:

Rigid cumulative:

Oleg Bondarchuck on an Aeros Combat won the day taking the second start time coming in first thirty seconds in front of Kevin Carter also on an Aeros Combat, who took the first start time. A couple of Wills Wing pilots made the top ten today with Nick in second. Jonny grabbed the bag at the finish line for the third day in a row, coming in third. He won one hundred dollars grabbing the bag on the first day.

Kevin hyper extended his leg on landing, so we'll see what happens tomorrow. Russell Brown broke a couple of toes before the meet and is still flying.

Paris Williams after not flying for a while, is doing very well.

The task for the flex wings was shorter at 60 miles. They flew northwest out to Coleman, south back to the top of the Green Swamp, north again to Center Hill and then 12 miles southeast to Quest.

Flex wings:

Flex wings cumulative:

As you can see from the times above, the tasks were under called given the great conditions. The clouds were much better than we thought at first. There was no over development. There were no cunimbs. Here's the BLIPSPOT for 4 PM at Groveland that I called up after I got back:

Dr. Jack is calling for zero lift at 4 PM and a high level of convergence and no surface heating (shade). The height of the -3 at 120 feet. In fact it was beautiful, sunny, warm, cu's every where. Pilots were piling into goal. Sixty flex wings made it back. All but one rigid wing made it back.

Here's the satellite photo showing cu's well up into Georgia:

Joerg Bajewski sends this photo from the air over Quest:

Sun, Apr 17 2005, 4:00:03 pm EDT

An new revolution in rigid wings.

Felix Ruehle

To see a list of and then listen to archived interviews on Oz Report Radio click here.

Felix Ruehle describes the changes and improvements to his line of rigid wings found in the VR.

Please send suggestions for interview subjects «here».

How to catch our Ozcasts.

Discuss Oz Report Radio at the Oz Report forum

A.I.R. ATOS VR|Felix Ruehle|Jim Lamb|photo|Ron Gleason

Thu, Apr 14 2005, 5:00:06 pm EDT

Rejoining the church of Felix Ruehle

After a blown out day yesterday we all got to try out our new VR's after a demonstration and lecture by Felix Ruehle on how to assemble the VR. I found out that you can pull the stinger,though it stays attached by the cord and bungees, to allow you to latch the two wings without additional help.

You can see a few photos that help explain how to set up an ATOS VR here.

I had a couple of sweet flights on my VR and low and behold I'm getting use to flying a rigid wing again. Unlike previous ATOSes the VR is very responsive and you can reverse a turn with a quick flip of the control bar. Turning it is merely a matter of thinking about turning (and a slight movement of the hands).

Ron Gleason had his VR flying at 90 mph with his hands at his chest. I found it easy to fly at 60 mph and it felt quite stable.

The VR has a moveable tail and a very large flap. These two innovations seem to make a significant difference in the speed range and handling of the VR relative to previous ATOSes. I hope to get many different reports over the next few days. Jim Lamb reported flying it with the bar above his head at 24 mph.

A.I.R. ATOS VR|Felix Ruehle

Thu, Mar 31 2005, 3:00:03 am EST

For the US National Championships

We heard today that our VR's should be coming into Miami on the 11^th or 12^th. Talk about at the last minute. Also that Felix Ruehle is coming this year to support the AIR ATOS pilots (Christopher Lohrmann did it last year). In addition, well known Austrian hang gliding pilot, and Viennese cop, will be flying one of the prototype AIR ATOS VR's.

Will the ATOSes actually get here in time? Well, with Felix coming they had better.

A.I.R. ATOS VR|Felix Ruehle

Mon, Dec 6 2004, 1:00:01 pm EST

A dramatic curve as an update.

I just picked out the most visible change from the V. It looks like an add on to the V.

Felix Ruehle «felix» sends and writes:

At least the winglets fit nice into the bag.

First we thought about V2, then V Race, V Rocket or V Raumauf.

The size of the glider is between the Atos V and VX

span / aspect ratio take off weight / glider weight / packing size

ATOS VS 11.8 m, 11.4 m   / 11.8 / 83-122 kg / 35 kg  / 5.15x0.46x0.2m
ATOS V   14.1 m, 12.8 m   / 12.1 / 90-150 kg / 37 kg  / 5.85x0.46x0.2m
ATOS VR 14.7 m, 13.74 m / 13.3 / 90-150 kg / 40 kg  / 5.15x0.48x0.2m
ATOS VX 16.0 m, 14.1 m   / 12.6 / 110-231 kg / 47 kg / 5.85x0.46x0.2m

We displayed the VR on Saturday at the Thermik exhibition in Böblingen. However the glider is little smaller than the VX it should have the same induced drag as the VX and approximately the same sink, but faster with a shorter roll rate. The glider has a adjustable tail which is coupled with the flap.

(editor's note: I've asked Felix to clear up a few issues I have with the numbers above.

To me the VR looks like a way to update the V (and replace it) as many of us have been converted to the VX for competition. The VX was originally created as a tandem glider but is very rarely used for that purpose. It is now the standard competition glider. The VX I sold a few months ago won all three of the competitions that it was entered in.

Of course, this will add confusion to the marketplace. We'll see what happens at the competitions this spring in Florida. Yes, it continues to look like there will in fact be two of them. I'll keep you posted.)

Fri, Oct 29 2004, 6:00:00 pm EDT

Cruising into the Moyes Boys Reunion with six ATOS VX's.

Felix Ruehle|Jamie Shelden

http://www.a-i-r.de

Felix Ruehle flew from Stuttgart, Germany into Wallaby Ranch to help with the delivery of six new ATOS VX's . They were setup and flown right in the middle of the Moyes Boys Reunion las weekend. After slow sales for the C and the V models here, the VX has made the US one of the top markets for AIR's ATOS rigid wing gliders.

Felix says that there was good flying, with many tandem flights on the VX (you can find out more about tandem flights on the VX at the AIR web site) and plenty of interest in the VX.

Here he takes Jamie Shelden for a tandem flight:

Photo by Jamie Shelden

Wed, Oct 6 2004, 7:00:01 pm EDT

It's built in Bend and Redmond, Oregon at the Lancair factory and the Windward-Performance factory.

Felix Ruehle|Gary Osoba|Greg Cole|Ian Duncan|record|Rohan Taylor|sailplane

I spent four hours over at the Windward-Performance factory today watching Greg Cole, Greg's dad, and Doug Taylor building new SparrowHawks, ultralight (FAR 103 legal) sailplanes. They've produced a dozen so far and have orders for twenty three according to Doug. It takes about a month to produce each plane, and they are seriously considering adding additional workers to ramp up a bit to get them out faster. Sales have been good of late and there is interest in dealerships in the US and Europe (where in Germany ultralight sailplanes have just been made legal).

The factory is a third of a hangar at the Bend airport (eastern Oregon just east of the Three Sisters) next to a company that puts Lancair kits together for pilots who don't wish to build these carbon fiber airplanes for themselves. The fuselage, wings, tail and stabilizers are laid up at the Lancair factory about ten miles to the north in Redmond (not Microsoft's Redmond) by their carbon fiber shop using molds developed by Greg and Windward.

Prepreg carbon fiber sheets are used in the construction of the SparrowHawks, and after the schedule of precut sheets are laid out in the mold, they are vacuum bagged and heated incrementally to 270 degrees Fahrenheit to cure the very high strength epoxy. Remember they are building a certifiable sailplane that weighs 150 pounds. It is very strong and very light (see their web site for more details).

I saw the two molds for the fuselage at the factory. They store them there and then haul them up to the Lancair factory when they want three new fuselages produced. They also take up the other molds when they do a run at Lancair.

The halves of the fuselage are glued together using a high strength epoxy type material - Hysol - this is gun barrel grey from the aluminum in it and costs $400 a gallon. It is used for military work with carbon fiber. Doug mixed up a batch while I was there and used it to glue some I-beams into the wings.

Greg, the president of Windward, was working on a tail section sanding it down, and also on a carbon fiber carrier for the tail section that you would clamp on to move the glider around. With a "normal" heavy fiberglass sailplane, you would have a clamp on wheel to put on the tail boom in order to help move the glider around on the tarmac. Greg had designed and built a carbon fiber clamp on section with a long carbon fiber hollow pole and you carried the light tail section instead. With a wing wheel on, it would be easy to drag the SparrowHawk, on its main wheel (non retractable like the Silent 2) as it is so light, to anywhere on the runway. You could also just hook it up to the hitch on your car and roll it down to the end of the runway if you didn't want to walk.

Being cured to 270 degrees means that the Sparrowhawk can handle temperatures up to 250 degrees, meaning that you can pain it any color you like. I saw one SparrowHawk with a special paint job that had clear coat on the undersurface of the wings. Clear coat is much harder to accomplish on any craft and it requires much sanding, and you have to arrange for that yourself if that's what you want as Windward can't take the time to do it.

Greg said that experience in the field with the SparrowHawk was showing that even though it is very light and has only an eleven meter wing size that it can keep up with the big heavy sailplanes because it can climb better and is only a little slower in glide because of its high wing loading. I saw one SparrowHawk that was built to allow for water ballast. In competition SparrowHawks are flown in Sport Class.

The production tolerances of the SparrowHawk are 1/20,000 of an inch. This is the thickness used for the Hysol adhesive. The molds are made from carbon fiber so that they do not expand with heat, very important when you go to 270 degrees. The jigs being used at the factory are checked with an optical transit to be level and are constructed, as you would hope, of heavy steel and carbon fiber.

Foam is used in flat or less curved areas of the wing and fuselage to stiffen these areas. The foam is stiff, but flexible enough to allow it to be fitted into less curved areas which need the additional stiffening.

Greg Cole works as a design consultant to Lancair and other aircraft companies. His is the most sophisticated and up to date carbon fiber operation that I have seen or am aware of. I have previously visited the LightHawk facility, spoken with Ian Duncan, who does the cool carbon fiber parts for Moyes, and spoken often with Felix Ruehle at AIR you uses carbon fiber wet lay up in fiberglass molds (at $35,000 each). I have spoken with Leo about the elements of the Silent 2.

I have only covered a small part of the production process that I got a glimpse of at Windward. I am not knowledgeable enough about carbon fiber production to be able to understand and explain all the various elements of that process that Doug and Greg spoke to me about. It was fascinating to be there and be exposed to it and I very much appreciate them taking to time to show me around.

In the future Windward hopes to build more and different sailplanes. They are currently the largest sailplane manufacturer in the US (the only?). They deal with the problem of product liability in the aircraft industry in the time honored fashion by going bare. Come and take away the jigs and the molds.

I saw plans for a motorized version of the SparrowHawk and will have a picture of the motor up soon. The motorized version will also be a legal ultralight. I also saw plans for a 15 meter version (who knows when) that will use the same fuselage. This will be heavier. It will allow for water ballast.

The 15 meter version will have a much thinner wing that the existing 15 meter fiber glass ships and have equivalent wing loading to allow it to race with these ships. Overall it will be much lighter, and about 400 pounds lighter when fully loaded, allowing it to turn tighter. Tentative name - DuckHawk.

The current eleven meter SparrowHawk is seen by Greg as a light fast sailplane that can get up earlier in the day than the standard sailplanes and stay up in light lift both at the beginning and end of the day. But during the middle of the day it doesn't give up in speed what the slower aircraft like the LightHawk does. (By the way, I believe the current LightHawk is 230 pounds.)
 
Gary Osoba flew Doug Taylor's SparrowHawk last year in Big Spring, Texas and Kansas and set three ultralight sailplane world records. Greg feels that if good conditions return to Texas the SparrowHawk could set many new ultralight sailplane world records, and even general sailplane world records. There will be a bunch of new SparrowHawk owners next year and many of them are experienced sailplane and hang glider pilots.

The SparrowHawk has yet to be flown and tested by Dick Johnson in Dallas to determine its measured performance values. Hopefully that can take place soon. Current SparrowHawk pilots are letting other experienced competition sailplane pilots fly their SparrowHawks and getting good feedback.

As a light carbon fiber aircraft the SparrowHawk is relatively stiff and the pilot feels the air more than is the case with soft heavy fiberglass sailplanes. This is both a benefit because it if more like a hang glider where the pilot feels the air, and a disadvantage as the pilot also feels the rougher air and just doesn't glide through it like they would on a "regular" sailplane. I guess each pilot has to see if they like this feel or not. So far the new SparrowHawk owners appear to like it.

I'll have pictures from the factory up soon. You can see earlier pictures of the SparrowHawk by searching for SparrowHawk on the Oz Report web site or going to the Windward web site.

A wing laid out. The tape on the left side marks where they are about to pain the Hysol.

Discuss SparrowHawks at the Oz Report forum

Tue, Aug 17 2004, 3:00:01 am EDT

A few tips. DHV certification.

Bob Lane|Dustin Martin|Felix Ruehle|Jim Lamb|Pat Denevan|US Nationals|Vince Endter

Want to keep the tip from scuffing? Put just a little Shoe GOO on the bottom surface. If you are dragging the tip around a lot on an asphalt surface you may need to add more, often.

I mentioned earlier the fact that Felix Ruehle flew with an extended extended stinger on his VX at the Worlds in Austria. The VX already has an extended stinger relative to the V (although you can special order the V with an extended stinger) and Felix was checking out the further extension. Felix loved it.

AIR sent me an extension for my VX extended stinger (the standard stinger on the VX). It is a 295 mm or 11 3/4" long.

I didn't add the extension to my stinger at the US Nationals as I was in the middle of a competition and didn't have the proper amount of time to do it right (drill the extra holes and line up the stabilizer with the wings). Hopefully, I will have a chance soon.

I also didn't feel any great need to have it on in Big Spring as the air was so nice.  Perhaps I will be someplace where I really wish I had it.

The first ribs on my VX were being slightly crushed by the downtubes, just like they are on the V and C (thanks to Vince for checking this out). This happens when you let the downtubes flop from side to side when packing up the ATOS. You can prevent it by holding the down tubes vertical when putting them away.

To repair the downtubes (which suffer only very minor damage) you can put a bit of carbon fiber over the crush point and then put heat shrink over the repair.

AIR makes and sells a repair kit that has carbon fiber in tubular form which makes it easy to do this as well as the properly sized heat shrink. Contact your local AIR ATOS dealer or Bob Lane at QuestAir (www.questairforce.com) on the east coast and Pat Denevan on the west coast to order the ATOS repair kit. Jim Lamb and Mark P. should be able to get it for you also.

On my last flight in Zapata, I took out my first ATOS down tube. The weaklink was just fine.

Putting an asymmetrical load on the control frame by taking out one down tube (or even bending one normal weak link) can put a torque load on the base tube which can split/separate the top and bottom halves of the base tube.

The base tube halves are only glued (epoxied) together. There are no strands of carbon fiber running from top to bottom, so this is a (designed?) weak point. I have now seen numerous ATOS base tubes that have been repaired (which is easy to do) to fix this problem.

Older ATOS carbon fiber base tubes would break at the spot where AIR cut into the carbon fiber to place the cleat. According to Vince Endter, AIR redesigned how they attached the cleat after he discussed this weak point with them. I haven't seen any of the newer ATOS base tubed break at the cleat point.

I easily fixed my base tube (and the down tube), but at first I didn't even notice that there was a problem. It took Dustin Martin's sharp eyes to see the little crack and then when we put weight on the base tube we could see the split along the front edge that would widen as we placed more weight on it.

I now have plenty of carbon fiber connecting the top and bottom pieces of the base tube, so my repaired base tube is probably stronger than the new version. Doesn't look quite as nice though.

I have a prototype AIR ATOS VX, which used the V version of the control frame. According to Felix, the other VX's that have been shipped to the US have a beefier control frame. After all, the VX is built for tandem and weighs 11 more pounds that the V.

I will review the new beefier control frame when it arrives.

BTW, VX's are now DHV certified

Fri, Jun 18 2004, 8:00:01 am EDT

Without the help from Felix Ruehle we wouldn't be here.

Belinda Boulter|Felix Ruehle|photo

In my previous reports I did neglect the fact that AIR has been very very helpful to the US team by allowing us to rent (in my case trade services) for ATOSes. My ATOS rental (trade) was much above the market rates, but the other US rigid wing team members were renting gliders at $500 for the two week period, far below market rates.

Felix was also here supporting all the ATOS pilots and Christoph showed up to support them on the last two days. Felix and AIR have been fantastic and it is much appreciated.

Belinda took this shot of the AIR ATOS van at Emberger Alm. The photos on the van seem to replace the background.

Discuss support at the Oz Report forum

Mon, Jun 14 2004, 8:00:00 pm EDT

Light thermals and a northeast wind.

Belinda Boulter|Brian Porter|Bruce Barmakian|Corinna Schwiegershausen|Felix Ruehle|Larry Bunner|Manfred Ruhmer|Ron Gleason|The Worlds|weather

http://www.drachenflieger.at

Larry Bunner asks what did the German fellow present about tucks that was useful information in the film session (I can't say discussion, because none was allowed) yesterday. While the results are for gliders that are now out of date and don't represent very well what we are flying, there were some useful bits.

The main point of the research was to determine the force that the pilot would have to pull in with when experiencing a tuck of the nose up variety in order to be able to hold the bar to their chest. The answer was that he/she would have to pull in with a force of about 1 G or about the pilot's weight. I.e. do a chin up on the bar to hold it where it would do you the most good.

If you think about it, this isn't so hard to see. The nose goes way up, you are left hanging below. You need to pull your weight up to get to the bar. The research didn't address the dynamic issues, i.e. how fast the glider was rotating, that might make this little maneuver a little harder than it appears.

Also it was demonstrated that a tail on a topless (first generation) flex wing hang glider provided for significant tuck recovery. Sprog systems have changed dramatically since these original topless gliders, so it is unclear how much additional benefit would be provided by a tail in this situation on a modern topless flex wing.

The day started off fully cloudy and stayed that way until around 4:30. There was a thin layer of clouds covering almost the whole area at about 8,000' with some cu's below. The meet weatherman predicted that the clouds would break up late in the afternoon.

There was also a strong northeast wind, maybe twenty five km/h that was quite visible in the clouds just above us. This is said to be the worse wind direction for turbulence and lee side rotors and down draft conditions. At least the weak thermals under the dark cloud cover would mean that things would not be too turbulent.

The task was an open window start between two and three o'clock with the pilot allowed to choose the time that they woyld start, with no intervals. This was done to allow for the fact that the lift was weak, and it was unclear when would be the best time to go for each pilot.

The launch conditions were predicted to be poor with a side component from the left, the east. Only with some sun light and heating would it straighten out and allow for safe launches.

The prediction was right on, and the launch line got stuffed up right away with a few pilots off before 1:30 in a good cycle but then maybe one or two every five minutes as the flag continued to straighten out from the east.

I pushed, but with poor conditions it didn't help much. Finally at 2:30, half an hour after the open start window has opened, I got to launch. I had originally wanted to launch at two in order to take advantage of the forecasted better conditions later in the day, but now I'm happy just to be launching before the start window time stops.

The lift was quite good to the right (west) of launch to cloudbase at 8,000' (quite low for what we have been experiencing here), and I was able to make it to the ridge before the start cylinder in plenty of time to get the start time just before 3 PM with 7,500'. There were quite a few pilots with me who no doubt also thought that it would be a good idea to start late.

The task was to a turnpoint upwind 12 kilometers on the Kreuzeck Gruppe, the mountains from which we launch, with a five kilometer entry start cylinder around the first turnpoint. The turnpoint (also the start point) is at the launch elevation and very much in the lee of the prevailing winds of a high peak.

Ron Gleason was a couple of hundred feet below me when we made our five kilometer dash on the lee side to get the first turnpoint point.  I dropped 2,500' in the downwash from the winds and just barely made the start point without smacking into the hill side to get within 400 meters of it. Then it was a race back in the down wash to get to a nice low spot where the lift was 50 fpm and the air was again calm.

Ron didn't make it and went down near the start point as did Vince earlier. Jim Yocom would soon join them. Many pilots would not be able to get high enough to make the start point. Bruce Barmakian made it and was heading back toward the second turnpoint which was here on the lee side, twenty four kilometers to the west and up on the hill side.

I worked a bunch of light lift but it only got me to within four kilometers of the second turnpoint. Due to a few equipment distractions I was unable to concentrate in the generally wonderful light lift that was coming off the sunny hill sides as the clouds broke up.

Bruce made the second and third turnpoints and the went down four miles past the third one. Many pilots landed before being able to go over the Gailtaler Alps to our south to get the second turnpoint on the Karnischen Alps on the Italian border. Bruce reported not getting much over 7,000' after leaving the Kreuzeck Gruppe.

Manfred and Brian Porter completed the task. Felix Ruehle won the day in class five by going back a couple of times to get the start point and hanging out over launch to wait for the sun. No class five gliders made goal. David Chaumet was second. Bruce Barmakian was third for the day. The day was worth less than 500 points.

Junko crashed on launch in the very very light conditions. I watched the whole launch and from what I saw the Swift is way too heavy for her to be able to launch in such conditions. It is my understanding that it is not repairable by tomorrow or for the rest of the meet. She, of course, is very unhappy, but also unhurt.

Latest news is that she might have a new wing for tomorrow.

Corinna won the day. Kari flew but was too nervous to go deep into the canyon on the lee side of launch where the good lift was and didn't get above launch. The day was worth less than three hundred points and Kari is still in first place overall.

Belinda takes this shot of a Quick Sliver just after launch at Emberger Alm over Berg.

Sat, Jun 12 2004, 8:00:01 pm EDT

The AIR web site didn't list the weight for the C.

Felix Ruehle

http://www.a-i-r.de

I wrote earlier about the weights of the ATOS C, V, and VX. I misread the AIR web site. It states that the ATOS weighs 73 pounds. But this is the standard model (this is a weight that we verified in Florida). This is the model before the C and the weight increased for the C with incremental changes that were made in going from the standard model to the C. The C weighs about 81 pounds and the V about 85 pounds (the additional weight is the weight of the tail).
 

The AIR web site (in the English only part - http://www.a-i-r.de/pages-e/navi_e.htm) states that the ATOS weighs 33 kilos. The German portion of the AIR web site states that the V weighs 38 kilos. I never weighed my C. According to Felix Ruehle the C weighs 1.1 kilos less than the V.

Discuss ATOS V at the Oz Report forum

Sat, Jun 12 2004, 8:00:00 pm EDT

The meet organizers call day six and day seven due to a cold front over us.

Belinda Boulter|Christian Ciech|Felix Ruehle|Flytec 4030|Icaro 2000|Jim Yocom|photo|prank|record|Ron Gleason|USHGA|Worlds 2004

http://www.drachenflieger.at

A couple of corrections. Uschi Broich's glider was damaged, but not destroyed by the helicopter. She's not happy about having landed safely with an undamaged glider and then being rescued (when she wasn't injured) by a helicopter that did damage to the glider. Her glider has been fixed, and she will fly on the next competition day.

The ATOS with the broken spoiler wire was damaged after landing, with a sail that was totaled, but the d-cells were in excellent shape. Johann and Felix reported that at the area where the ATOS landed it was always blowing up when they got there, so it was clear why the landing was so soft (and why the glider got picked up and tossed around later).

The "professional" rescue crew that took Kari up to retrieve her harness and glider were nonplussed to find that an amateur crew of women pilots who had started out after them had arrived first and had things well in hand by the time that they got there. Kari was pleased.

Belinda takes this shot of Kari with all  her scars.

Icaro 2000 has sent Kari Christian Ciech's Laminar from the World's in Brazil and Kari still has her base bar to put on it. She will probably be flying with her own harness which had minor damage and a Flytec 4030 Race and Garmin 76S from Ron Gleason (he's using his Flytec 5030). Looks like she'll be able to continue.

Saturday the forecast was for embedded thunderstorms, and sure enough at 1:30 PM it poured here in the valley as we were watching the Flugtag at the lake next door. That ended Flugtag.

This Flugtag was being held in conjunction with the Worlds, and would have presented a great opportunity for people to see unflyable things smashing into the water, next to rigid wing pilots "landing" at goal.

Personally, I don't get the real significance of Flugtag. Is it a way of proving that man was not meant to fly? Is the object to build something that can't possibly "win." It is just a fun way of destroying Styrofoam and polluting a small lake?

There were hundred of people who came out for a day of eating, drinking, looking at new car models, and watching the papier-mâché
constructions dive right off the edge of the plank into the water twenty feet below, without even the pretence of attempting flight.

Certainly more people came to watch this version of a college prank and small time Rose parade, then came to watch us pound in real aluminum and carbon fiber at the designated landing zone at Berg. But then it was advertised very heavily and had a predictable time for the carnage to begin. Our lz did have plenty of beer and other drinks in the barn converted to a bar, so you would think that it had some attraction (and there were a good number of locals there).

It rained all afternoon in Greifenburg so it is hard to imagine that we will be going up to fly on Sunday.

I had a long interview with Felix Ruehle for an article on the V and VX for USHGA HG/PG magazine. I will have additional comments in the Oz Report about what I learned from Felix.

Here you'll find the 3 D track log IGC file from the last competition day so far. If you have SeeYou (www.seeyou.ws) and have downloaded the satellite photos for this area you will have a good idea of what the surrounding terrain looks like if you follow the flight. You can download the ATOS 3D symbol from the AIR web site (www.a-i-r-.de) blow it up to about 400 feet and really get a good idea.

Sunday is is called by the organizers before we have to go up the hill.

On Sunday evening the head of the German Hang Gliding Association showed the old films of the DHV tests of gliders rotating when released from below the 200+ meter high bridge. I have earlier published collages taken from the films.

He started off referring to the fact that we had a couple of tucks and tumbles lately here and then asked who among the pilots in the small audience (about 30 people) had tucked or tumbled. Seven or eight pilots raised their hands.

He then went on to refer to the "classical" tuck during which the nose comes up high then rotates through. I politely asked him what he meant by the word classical. (He is a German speaker using English and it was unclear to me what he meant, and unclear to him after I asked whether this was the correct term). He stated that this meant "most common," or reported to be the case in 80% of the tucks.

This got my interest, because this was not the case in my case, nor was it the case in Kari's case. I also thought it was quite revealing that he didn't ask Kari or Uschi if this was true for them, nor did he ask those who had raised their hands, if this was true for them. I.e., was anything he was about to say actually relevant. And, as he was stating this as scientific fact, you would think he might actually look for some recent evidence.

A bit later he referred again to Kari's tuck and I raised my hand again to ask if he would just ask the participants here if what he was saying was true for them or not. This caused quite a commotion as he didn't take kindly to my interruption and asked who was I to question him and disturb his presentation. I hate this when people ask who are you to bring up these issues instead of addressing the legitimate concerns.

After calming down he then asked a few pilots if the nose up situation was true for them: two said yes, one said no. Then he asked Uschii (she said yes) and Kari and she said no. The rest of the pilots who had tucked were not asked.

The point of interest here is that work that he was about to present while fine in and of itself, does not address the fundamental issue, what air conditions cause a glider to tuck and tumble. There are many causes for the situation where your angle of attack is too high for the air packet that you are currently in. (You can find extensive discussions of these issues in earlier Oz Reports.)

The conclusions drawn from the work are overly broad and often irrelevant to the actual conditions that the pilot faces. If the pilot has the opportunity and ability to hold the bar to their chest when they recognize that they are suddenly at a high angle of attack, this can in some circumstances be useful and possible. That's about all we can say. It is incorrect to "imply" from the research that in 80% of the "cases" the pilot could have saved themselves from a tuck and tumble by holding the bar to their chest.

I have no way to judge under what circumstances you will tuck and tumble, but if the pilot is flying in a normal fashion, it is the air that will determine this and not the pilot. Unless that pilot is flying in an unsafe manner, it is not the pilot's fault that the glider tucks and tumbles.

I was speaking with Jim Yocom on the way up the hill the other day. His feeling was that in all the cases where he had spoken to the pilot who tucked and tumbled, the pilot reported that it happened so fast that there was no time to do anything. In the cases where the pilot tucked and recovered things happened much more slowly. Brain's record event at a certain rate, and if your brain can't record it, it happened too fast for you to actually do anything.

The meet organizers claim we have an 80% chance of flying on Monday. It rained on Sunday.

Thu, May 6 2004, 1:00:00 pm EDT

My impressions of the new glider from AIR.

A.I.R. ATOS|Belinda Boulter|carbon fiber|Felix Ruehle

http://www.a-i-r.de/pages-d/f_a_01.htm

Well, first of all I am, of course, very happy to be flying on and winning the latest competition with the AIR ATOS VX. Given my dismal showing at the Flytec Championship (people were approaching Belinda to ask if there was something wrong with me), it is a true testament to the superior performance of the VX that I was able to win the South Florida Championships.

The AIR ATOS - VX with its curved up tips is a very beautiful glider to see in the air. You could always spot Alex during the Flytec Championship, high over your head.

The VX, while in prototype, came in two versions - single and tandem. The tandem version, which is now the standard version, is heavier and beefed up to handle two people hanging from the carbon fiber keel. Alex brought the standard (tandem) version to fly by himself at the Flytec Championship and that is the one that I have now.

The VX is listed at 93 pounds (42 kg), the V is listed at 82 pounds (37 kg), and the C is listed at 73 pounds (33.5 kg). I have weighed my C and it is 73 pounds, I haven't weighed the VX yet. I didn't find the VX to be particularly heavy. I was able to carry it around pretty much like I did my C.

These weights do make one wonder what changes they made between the C and the V. The differences are not obvious, so I assume it is in the carbon fiber lay-up. Maybe they are just counting different things (bag or not?).

I asked Felix Ruehle about this. He wrote:

The new control system where the spoiler cable is attached inside, has 3 extra steel pulleys. The brake away safety parts at the down tubes add some weight. The sail is reinforced at the trailing edge and tip in comparison to the first ATOS. The Spoiler and Flap are painted white. The first spoiler were little lighter.

Still, these changes don't seem to be enough to make such a large difference in weight between the C and the V. The weight for the V includes the tail, which the weight for the C did not.

The tips of the VX are formed with a long aluminum tube and a thin carbon fiber shell that creates the leading edge. This is essentially just an extension of the tips found on the standard ATOS (or C or V) model with the outboard tube tilted upward a bit.

There is an additional rib that is jammed in placed (not connected) to the leading edge) tube to continue the airfoil profile further out to the 46 feet wing span (vs. 42 feet for the standard model). I assume that the tips are canted up to relief any force on them while the glider is on the ground.

Felix writes when I ask him about this:

The main reason is to have enough clearance at take off. Wings with higher aspect ratio tend to tighten turns. With the additional dihedral of the outer wing the glider fly stable in turns.

The glider takes a little bit longer to put together than the standard version, basically because of the additional requirement of putting in the longer carbon fiber leading edge shell and the additional rib. Otherwise it is the same as the V.

My VX came with a carbon fiber keel (the part in the sail), and without a whack tube. There will be a foam core to replace the tube. The carbon fiber keel is standard. The d-cells and the ribs have been beefy up on the VX. Otherwise the hardware was very familiar.

The stinger on the VX is longer than that found on the standard model, and this means that the tail is further back. I assume that this adds to the stability of the glider in pitch as there is now a longer lever arm from the center of lift to the tail.

I flew both my C and the VX with the longer stinger and perceived a difference in how the gliders reacted to pitch movement with more apparent dampening. This appeared to give the glider a steadier feel.

The VX is not yet certified but AIR has run the pitch tests at the DHV for it and it has passed those tests. You can read more about it at the AIR web site (see the URL above). I suggest looking at the German version of the AIR web site, as the English version is not up to date.

Fri, Mar 5 2004, 3:00:02 pm EST

The big glider for the smaller pilot.

Alessandro "Alex" Ploner|Felix Ruehle

Alex Ploner, Felix Ruehle's sponsored pilot, will be flying the AIR ATOS VX at the Florida meets, and the speculation is that he will be using dumpable ballast. Personally, I would be flying the small one with no ballast in Texas, and in Florida, maybe the regular size one without ballast.

Discuss ATOS VX at the Oz Report forum

Fri, Feb 6 2004, 8:00:00 am EST

Felix Ruehle|Ian Duncan|Icaro 2000

I fly with ballast. Ten kilos or twenty two pounds of ballast. I got the ballast for flying with my ATOS 145, which was designed by a big guy, Felix Ruehle. I figured gliders reflect their designers.

When I got to Australia and I was flying the flex wing gliders, I wondered why I was flying big gliders with ballast, when I could have been flying small gliders, perhaps without ballast. I didn't mention to Airborne or Moyes what size of glider I wanted to fly, and I just left it up to them to size the gliders for me.

Ballast in the air, or when landing has never been a problem for me, but I do dislike carrying around such a heavy harness, and putting it on is a major hassle. If it wasn't for this hassle, ballast would be a no cost option.

After I got back from Australia I thought I would check and see just how the wing loading of the various flex wings would differ for me, with and without ballast. Here's the chart I came up with:

The glider weights and dimensions were taken from their manufacturer's web site. The weights of the Combat L and the Litespeeds were modified to account for the changes recently made to them and the options chosen, as per Ian Duncan at https://ozreport.com/toc.php?8.024#1.

Hook in weights were taken from the manufacturers' web sites, as were optimum pilot weight from the Moyes web site, and pilot weight range from the Wills Wing web site. The values for the Icaro 2000 Zero-7 14.2 weren't available yet.

I then divided minimum and maximum hook in weights by the stated sail area to get the minimum and maximum recommended wing loading. Further, I took my hook in weight with (222 lbs) and without ballast (200 pounds), and determined my wing loading for each of the models.

 I was feeling that the gliders I was flying in Australia were a little "big" for me, even though I was flying with ballast. I wondered what the difference in wing loading would be if I went down a size or two in gliders and took off the ballast.

I found out right away that I could have had the same wing loading flying an Airborne Climax 13 without ballast, as I had with the Climax 14 flying with ballast (although I would have been two pounds over the maximum hook in weight). That makes me think that I could have flown a glider that wouldn't have seemed so "big" and not had to carry the ballast.

Looking at the Moyes Litespeeds, it seemed like I could have flown a 3.5 with no ballast and only had a .05 lbs/ sq.ft. reduction in wing loading, which doesn't seem like much.

The story is similar when you look at other gliders and compare wing loading with the middle or larger glider with ballast and the small gliders without ballast. Wing loading goes down, but not that much. I could maybe add a little bit of ballast.

Now wing loading doesn't tell the whole performance story and often there are differences in performance at optimum hook-in weight across glider sizes. But, I'm betting that these manufacturers are building pretty good gliders at all sizes, so it might not hurt to get the smaller model.

Also, how "big" a glider feels depends greatly on the conditions. If conditions are light and scratchy a big glider is just fine, thank you. In rough strong air in the mountains, the smaller, the better.

The table above bares a little study and reflection. You can read it into Excel and put the equations back in to make it work for your hook-in weight.

Felix Ruehle|John Vernon|tail|tuck

Felix Ruehle <felix@a-i-r.de> writes in response to John Vernon’s article:

The V-tail adds damping and pitch up moment.

It's not a question of tail plane or V-tail. A V-tail has other advantages but no disadvantage re protecting against a tuck.

The pitch up moment with deflected flap, for example, has about double of the certified value but that’s not the point. After the rotation has started, at low speed, the double pitch up moment is not enough. However with increased air speed, pitch damping and pitch up moment is higher and the effect of the turbulence is less.

We made further test with tail and I would like to write you more when I'm back. I’m off for five days in Portugal with Ana. At this time flying in Germany is great. Gert Langwald flew 385km and another pilot flew 315. The A-I-R team spent many hours in the air, too.

Adi and I have flown this year recording our g-loads. We flew in very strong conditions, for example, with 50 km/h north wind south of the Alps (don’t try this at home). The g-loading never exceeded 3g’s positive and 1.5 negative. Also at fast final glides of 100km/h or faster the loads were always lower than these figures.

I have heard that some pilots don't like to fly fast because they think that they will overload the glider. There’s no problem with flying at 70 or 75 km/h in very strong lift. The risk of flying slow is much higher. The minimum sink speed for the Atos is about 42km/h and I often fly at this speed, but not when I expect turbulence in strong lift.

Discuss "Tail plane Vs. V-tail" at the Oz Report forum   link»

accident|aerotow|airline|airspace|altitude|Angelo Crapanzano|bridle|Carlos Avila|certification|cloud|control frame|DHV|environment|equipment|Felix Ruehle|Florida|foot launch|general aviation|GPS|harness|injury|job|landing|military|Moyes Xtralite|parachute|Ron Richardson|safety|site|spin|Swift|tail|technique|tow|towing|tumble|USHGA|Wallaby Ranch|winch

David Cross <d.cross@chello.nl> writes:

I have recently had the unfortunate experience of departing controlled flight in an ATOS rigid wing hang glider. I have written this report to share the experience with my fellow aviators so that any lessons learnt may be shared and the accident assessed by those with a better insight in this field than I.

Description of Flight Conditions

I had launched in the mid afternoon with an aero tow from Aerotow.com's facilities near the town of Avila in central Spain. I was planning to fly some cross country under the tuition of the highly experienced Ron Richardson. It was my second flight of the day. On the previous flight I had found the conditions to be weak with the thermals broken and the climbs poor and I had not been able to stay up for long. The afternoon however improved with the cloud base lifting to about 7000' altitude (average ground elevation of 3000'), with promising cumulus development downwind to the east and no sign of the previous day's overdevelopment.

The second aero tow was bumpy but easy to handle on the ATOS with its excellent control harmony between pitch and roll. I was waved off in some lift over a small ridgeline to the south east of the field. I again found the lift to be broken and the climb weak. Ron was at this stage further to the east overhead the town and was calling a 300'/min climb on the averager. As I was at this stage too low to get over to him I focused on what I had in order to build more altitude. I scratched up to 4800' altitude and then ran for a good looking cumulus on the way to Ron's position.

Loss of Control

Entering the Thermal

I rolled right hand into the lift under the cumulus and worked hard to centre it. The conditions were choppy but not rough and smoothed out somewhat above 5000' altitude to a steady 300 fpm up. The conditions downwind were now looking really good and through each turn I was scanning to pick up Ron's Avian Cheetah on the horizon, and I could hear Darren Blackman heading in towards us on his Swift. Things were at last coming together after a week of poor conditions. I was relaxed, thoroughly enjoying the ATOS and looking forward to the afternoons flying.

Turn Reversal

I had in the last turn noticed a slight increase in lift in the southern sector of my circle. I glanced down to see if there were any birds marking the core and was presented with a magnificent stork circling left hand counter flow to me with slightly intersecting circles. After one more turn I saw that (as always) he was doing a better job than I and so I planned a turn reversal into his circle.

The reversal worked out well. As the stork slid under my nose I experienced a moderate pitch up from the stronger lift and eased the bar in to lower the nose and accelerate while rolling out of the right hand turn into a left hand circle. Due to the fair conditions I had been thermalling at 40-45 km/h (25-28 mph) indicated airspeed (IAS) with 20-25° of bank and had felt very comfortable at this speed.

(editor’s note: Unless the thermal is absolutely light (50-100 fpm) and full with no turbulence, I’m flying at 34-38 mph. The speeds indicated above are much too slow for the conditions described.)

As I had now accelerated into the stronger lift I estimate that the IAS was approximately 48-50 km/h (30 mph) as I started the reversal. The flap was set at 8-10°. The reversal was initiated with moderate spoiler application - I estimate ⅓ to ½ deflection. The altitude was now 6000' (about 2500' AGL due to the ridge below).

Departing Controlled Flight

As the left hand turn was established I felt a light short period aerodynamic buffet on the control frame and almost simultaneously experienced a very rapid nose down pitch rotation through approximately 90° of pitch. I estimate the pitch rotation rate to be 50 -60°/sec. There was also some left hand roll rotation, although this was less than the amount of pitch rotation. I was not aware of any significant yaw.

As the departure started my assessment was that the glider was auto-rotating and that I was in the incipient stage of a spin. I had been thermalling with the bar in the upper chest to lower chin position. As the nose down pitch started I rapidly moved the bar in to the mid chest position in an attempt to reduce the angle of attack, un-stall the wing and stop the autorotation. This appeared to stop the left roll rotation rate but had little effect on the rate of nose down pitch. During the latter part of the initial nose down rotation I estimate that the g loading on my body was 0 - 0.5 g (I felt almost weightless).

The glider then appeared to stabilize very briefly in the vertical nose down position before rotating extremely rapidly in pitch to the inverted position. This second rotation was violent and uncontrollable. As it happened I felt a powerful rearward pull from my hang strap and the control bar was pulled from my grip. I was thrown hard into the undersurface of the glider which was now inverted, next to the A frame. I estimate that this pitch down rate was well in excess of 90°/sec.

The glider now stabilized in the inverted position while descending in what appeared to be a relatively gentle oscillatory spiral. I was somewhat disorientated at this point and so may not be too accurate about the motion of the glider. I do however recall some spiral motion and some oscillation above and below the horizon.

I was lying on the undersurface of the wing to the left of and outside the A frame. I immediately checked the leading edges and tips and observed no apparent structural damage. I assessed that I had sufficient altitude and attempted to right the glider and reached for the A frame to do this. When I grasped the left down tube to attempt to right the glider, the glider entered a very disorientating oscillatory rotation but remained inverted. I assume this was caused by spoiler deflection when I moved the A frame.

After two rapid rotations it did not appear to be recovering. At this stage I was losing situational awareness with respect to the height remaining for recovery. In addition the gliders unstable motion had me concerned about the possibility of being knocked unconscious.

Parachute Deployment

I thus looked for clear air and deployed my emergency parachute hard in the direction of rotation half way between the right hand wingtip and the keel. The parachute deployed immediately and then appeared to semi collapse as the glider was rotated by the parachute deployment into the upright position, swinging me hard to hang to the outside of the A frame. The parachute then reopened immediately.

The system of parachute, glider and pilot now became extremely unstable with the parachute and the glider appearing to work in opposition. The glider appeared to accelerate and pitch nose up, causing the chute to collapse and then re-open before the cycle was repeated by the glider. From my vantage point the parachute was describing a sine curve-like path across the horizon while collapsing partially and re-opening in sequence with the pitch motion of the glider.

The glider and parachute appeared to be rotating rapidly about each other with the centre of this rotation somewhere between the glider and the parachute. At no stage was the parachute positioned above the glider. The centripetal acceleration of this system rapidly became very high. I estimate the g loading to be approximately 3 g and I was swung out helplessly under the wing clear of the A frame unable to control the system at all.

Stabilizing the System

I now broadcast a Mayday call, and informed Ron that I had deployed the parachute and was going down. I described my status and informed him that it did not look promising. At this stage the rate of descent and particularly the angular rotation appeared to me to be very high and I was sure that ground impact in this configuration would have severe consequences.

After several high g rotations I managed to grab the hang strap behind my neck and pull myself toward the A frame and grasp a down tube. Adrenaline is a wonderful thing. I then pulled myself into the A frame. This had an immediate positive effect. The parachute stabilized above the glider, the angular velocity reduced and the g loading reduced. I was now descending through about 500' AGL with a moderate oscillation but no angular rotation at all. I now called Ron to inform him that the situation was under control and proceeded to describe my probable touchdown position to him.

Touchdown

I descended onto the slope of a rocky tree covered ridge. Before impact I positioned myself as high into the A frame as possible as I was not sure what the rate of descent was and I wished to protect myself from any impact on what appeared to be very rocky terrain. I kept my legs bent to absorb as much shock as possible.

I was fortunate to impact into the crown of a moderately sized tree. The A frame took much of the initial impact of the branches. The glider was then swung out of the top of the tree throwing me out of the A frame. As I fell to the ground the glider hooked onto a branch and my fall was arrested with my feet 12cm off the ground. I was completely uninjured. I transmitted to Ron that I was down and safe and that he should cancel any ambulance.

The only apparent damage to the glider was a broken main spar and associated sail damage approximately ⅓ in from the right wingtip. This occurred on ground impact and not in flight. My assessment was that the glider was completely undamaged until ground contact.

Discussion

As with any aviation accident there are several lessons to be learnt. Most accidents are not caused by a single event but by a combination of factors. Often an accident could have been prevented if just one of these factors, however minor it may have seemed at the time, could have been identified and stopped. I will now discuss my background, what I think may have been the contributing factors to this accident and the lessons learnt from it. This is obviously my subjective opinion and I welcome any discussion on these points that may offer a more informed insight.

Flying Experience and Background

I am a USHGA intermediate rated pilot who has been flying for three years. I did my initial training in the French Alps mountain launching and completed my training at Wallaby Ranch where I also obtained an aero tow rating. I did a further foot launching course at Lookout Mountain where I obtained cliff launch, flat slope launch and assisted windy cliff launch ratings. My flying has taken place mostly in Florida and the Alps and has always been under the supervision of more experienced pilots. I currently fly a Moyes Xtralite. One month prior to the accident I had flown under the supervision of Chris Dawes in the UK where I did some winch foot launch training and some aero towing as an early season refresher. Prior to this I had last flown the previous late summer in the Alps.

I am a current airline pilot flying Boeing 747's and a current Air Force reserve pilot on fighter type aircraft. I hold a Glider Pilot's License although I am not at present current on sailplanes. I have some experience flying paragliders although I have not yet completed my license. My total flying experience is 8000 hours.

I have mentioned the military experience as I feel it is relevant with respect to my experience in spinning three axis control aircraft. My air force background has provided me with extensive spin training. I have been fortunate to have had the opportunity of spinning a variety of aircraft, from military trainers and fighters to general aviation aircraft, aerobatic aircraft and sailplanes.

Two weeks prior to this accident I carried out a maintenance test flight on a military trainer that included several multi turn full spins and recoveries. I thus feel that I may be considered current as far as spin identification, entry and recovery on three axis aircraft is concerned. This has relevance as there has been much discussion about the advantages of doing spin training on three axis aircraft before flying rigid wing hang gliders.

ATOS Experience

I had come to Spain specifically for the opportunity of flying the ATOS. At the time of the accident I had flown 11 flights on the ATOS for a total of 5.00 flying hours. All flight had been under the supervision of Felix Ruehle and I had been extensively and professionally briefed by him on all aspects of the glider.

Although this was my first experience on a rigid wing hang glider I had felt comfortable and confident on the ATOS from the first flight. I had on the second flight in smooth evening conditions flown the glider to the stall and found the recovery to be simple. I had confidence thermalling the glider in the moderate conditions I had experienced and at no stage had any reservations about the handling of the glider. I found the control harmony particularly pleasant and aero towing simple.

(editor’s note: An inexperienced hang glider pilot, new to an ATOS, was flying it too slow in a thermal.)

Equipment

The glider was a standard ATOS. I had for most of the week prior to the accident been flying another standard ATOS. The hang point for the accident glider (as on the previous glider) had been adjusted towards the forward centre of gravity (C of G) limit, appropriate to my hook in weight. On the accident glider my hang position was slightly higher than that of the glider I had flown previously in the week and the trim speed was slightly lower. Both the hang position and the trim speed were well within safe limits. The glider was fitted with an A.I.R. horizontal stabilizer.

I was using a Woody Valley Tenax harness with the parachute mounted on the right chest. The harness was fitted with a Metamorfosi Conar 18 Gore parachute, which was just over one year old and had recently been repacked by myself. No swivel was fitted to the bridle. My weight is 72 kg making a hook in weight of 87kg.

Airspeed information was provided by a Brauniger Galileo set to indicated airspeed (IAS) mode and a mechanical pitot system fitted by Felix. I used the mechanical system for airspeed reference as I had not yet calibrated the Galileo and was not sure of the reliability of the airspeed display.

Departure from Controlled Flight

I feel that the departure from controlled flight had two distinct phases, a non divergent autorotation phase, and a divergent pitch instability phase.

Autorotation Phase

The autorotation phase I would describe as a gust induced stall in the turn followed by an autorotation and an incipient spin (the incipient stage of the spin being where the aerodynamic and gyroscopic effects of the spin are still influenced by the initial flight path of the glider - in this case a left hand turn). Although the nose down rotation of this phase was rapid it did not feel to me to be divergent. I thus do not feel that the gust had at this stage placed the wing at an AOA/hang point loading combination that had exceeded any static stability margins.

I was surprised by the limited aerodynamic stall warning and the rate of the initial nose down rotation. For these reasons I think the gust onset was significant and rapid. All my previous spinning experience in aircraft had led me to expect an initial rotation rate in roll and yaw that equaled or exceeded any initial nose down pitch rotation. As the initial nose down rotation started I had reduced the AOA aggressively. This seemed to stop any further roll or yaw rotation but had little effect on the rate of nose down pitch rotation. At no stage did the glider enter a stabilized spin.

I feel that there are several factors that could have contributed to the initial autorotation.

Firstly the glider was trimmed slightly slower than that to which I had been used to on the previous ATOS I had flown. As stated this was well within safe limits but may have caused a tendency towards slightly slower flight if I was distracted.

Secondly, I was using flap to thermal. This would move the bar position slightly back and I would, if focused primarily on bar position, have the tendency to move the bar further forward than required.

Thirdly, I had completed a turn reversal prior to the autorotation and the spoiler deflection would have caused some nose up pitching moment. If not corrected this would cause an obvious reduction in IAS and place the glider closer to the stall.

All the above factors are conducive to slower flight. However I am accustomed to flying aircraft that require accurate speed control and feel that I was very aware of the IAS while thermalling. I was also aware that the spin behavior of rigid wing gliders can be unpredictable and had no desire to explore that environment. My thermalling speed of 42-45 km/h (26 mph) felt comfortable for the conditions I was experiencing. I have since been informed that it was perhaps on the low side but not unsafe.

(editor’s note: Pilot is unaware that he is flying too slow.)

I had thermalled at similar speeds in equivalent conditions for most of the week without ever approaching any stall margins. The accuracy of the airspeed reference must also be considered. As mentioned previously my primary reference was the mechanical pitot system as I felt it was more accurate than my as yet un-calibrated electronic reference.

Some points with respect to the turn reversal technique. I normally unload the wing (thus reducing the AOA) before initiating any reversal in order to improve the roll rate. This obviously also results in an increase in IAS. Whether my technique was sufficient to counter any pitch up due to spoiler deflection may be debated. I did not notice any significant pitch up during this particular reversal. My limited experience on the ATOS could of course preclude this.

In addition I had experienced acceleration on entering the increased lift prior to the reversal. I had countered the nose up pitch that this had caused and so feel that my IAS margins on entry to the turn reversal were probably sufficient for normal conditions. I had as well been briefed on the "rule of thumb" safe range for forward and rearward bar positions and at all times flew within this range.

I thus think there must have been some significant gust effect present. Simply approaching the stall in a turn should not result in the almost immediate and rapid rotation experienced with minimal stall warning. I have described the conditions as moderate. I was experiencing an average climb of 300 fpm with maximum instantaneous readings of 1000 fpm.

However, Ron Richardson reported some strong turbulence while descending through the airspace I had been flying in, shortly after I deployed the parachute. My assessment is that a gust rapidly exceeded the critical AOA of the wing. As I was not yet fully established in a stable turn, there would have been some asymmetric loading on the wing, possibly resulting in the auto-rotation. I feel that this is supported by the fact that my rapid reduction in the AOA had no appreciable effect on the pitch rotation rate.

Pitch Instability Phase

I will now discuss what I consider to be the second phase of the departure. During the initial auto-rotation I had not experienced any reduction in g loading on my body - the hang point still felt loaded. Although the initial nose down rotation was high, I still felt that I had some control input and that the glider would recover. However, as the glider passed through about 60° nose down I experienced a reduction in g loading and felt almost weightless.

From this point I felt I no longer had control of the glider and I was unable to hold the bar in any longer. This is when the rapid rotation to the inverted position occurred and I lost my grip on the control bar. Perhaps the excessive AOA of the wing combined with the unloading of the hang point caused the static stability margins of the wing to be exceeded, causing a divergent rotation in pitch. The first auto-rotation phase initially felt controllable. The second phase of pitch instability was definitely not controllable.

Lessons Learnt

Thermalling at higher speed, steeper bank angles and higher g loadings, while not necessarily providing an increase in stall margin, will improve the damping in pitch and make a departure less likely.

It would be of value to calculate the exact stall speeds for the actual wing loading at various appropriate bank angles. With an accurate IAS reference sufficient margins could be applied to these calculated stall speeds for safer thermalling. An accurate IAS reference is obviously necessary. Of even more value would be a vane type AOA reference (Here's hoping!).

I found the ATOS easy and a pleasure to fly. However, in retrospect I feel that more time spent exploring the performance of the glider in smooth air would have been of benefit. I think in particular, the effect of flap on trim speeds and bar position, spoiler effect on pitch in turn reversals and approaches to the stall in wings level and turning flight should have been more fully explored before flying in more challenging conditions.

I think that my initial reaction to the auto-rotation phase was correct. Moving the bar in reduces the AOA and places the centre of gravity in the best possible position for dive recovery. Should this happen again I will do the same while attempting to hold on tighter. I do however feel that it was impossible to maintain grip on the control bar during the rotation to the inverted position.

Some comments on pilot experience. I was very excited to be offered the opportunity to fly the ATOS by Felix, as I consider myself a low time hang glider pilot. His briefing was comprehensive and gave me confidence in the glider while making me aware of how it differed from other gliders I had flown. I flew the glider conservatively and felt very confident with the general handling.

The afternoon following the accident I flew another standard ATOS in moderate thermic conditions for a 1 ½ hour flight. While understandably nervous at first the pleasant handling of the glider allowed me to settle down and soon regain my confidence. In summary I experienced nothing in the handling of the ATOS that should exceed the abilities of an intermediate pilot. In most respects I found the ATOS easier to fly than an intermediate flex wing hang glider.

Some discussion on three axis spin training for rigid wing pilots. I feel the main benefit of this would be spin entry recognition and reduced disorientation. The spin entry techniques and recovery procedures for a three axis aircraft are different to that of a rigid wing hang glider and themselves can vary dependant on the design of the aircraft. Practicing these procedures would I feel have limited benefit for rigid wing pilots and may even reinforce incorrect techniques. In this accident the main benefit to me of my spin training was recognition of the initial situation and orientation in the unusual attitudes experienced.

Some points on the parachute deployment. It has been suggested, considering the glider was undamaged while inverted, that I could have tried harder to right the glider before deploying the parachute. In retrospect I am glad I did not. I lost a lot of height trying to stabilize the spinning parachute/glider combination. Had I deployed the parachute any later I might have impacted before stabilizing the system. At the time I did not feel that this would have been survivable.

I have discussed this with Angelo Crapanzano from Metamorfosi. He commented that although I was experiencing high g loadings, because the centre of gravity of the pilot/glider/parachute system would have been very close to the pilot/glider combination, my rotational speed would actually have been quite low. In addition he said that my descent rate would perhaps have been even less than when I had stabilized the system. He thus feels that even when the system was not stabilized, it was survivable. The perception from the pilot's point of view remains unpleasant.

In addition it is not certain how the glider may have reacted in the attempt to right it and there is a strong possibility of pilot injury in attempting this. This may then preclude parachute deployment. I thus feel strongly that if one is fortunate to survive a loss of control situation uninjured, the priority is to get the parachute deployed immediately. Considering the instability after parachute deployment, I feel the priority should be to get ones mass as close as possible to the hang point.

Angelo Crapanzano recommends that one gets as close as possible to the nose of the glider, or at least in front of the hang point. This can however be difficult and the A frame is a familiar refuge when under stress and can provide impact protection. It would have helped if I had held onto some part of the A frame before deploying the parachute, as this might have prevented me from being flung away from the A frame as the parachute deployed and righted the glider.

Had I been able to remain closer to the A frame the spiral motion might not have developed. I also feel that some thought should be given to the option of releasing from the glider prior to parachute deployment. All my complications were due to the fact that I was still attached to the glider.

I am very pleased that I had the Conar HG18 parachute. The rate of descent once stabilized was acceptable and the opening time impressively fast. It worked as advertised.

Some discussion on communications and search and rescue procedures. I was able to transmit a Mayday to Ron Richardson seconds after deploying the parachute as I had a transmit button fixed to my thumb. Ron demonstrated professionalism and true airmanship. He acknowledged my call, was overhead my position within minutes, plotted GPS co-ordinates and arranged a rescue. He then landed in a difficult location and was at the accident site within 30 minutes.

Had I been seriously injured Ron's actions would have been potentially life saving. The lessons here are to always fly with someone, be able to communicate effectively with them, even under duress, and always be prepared to assist effectively in an emergency. I had water in my harness but no first aid kit or emergency rations. This has been rectified.

Conclusion

In summary, I suggest that this accident was a result of a gust exceeding the critical angle of attack of the wing by a large margin. This resulted in auto-rotation with a rapid nose down pitch and unloading of the hang point. The static stability margin of the wing was exceeded and the wing experienced a divergent rotation to the inverted position.

Contributory factors were the relatively low indicated airspeed while thermalling, the effect of flap on the control bar position, pilot technique in the turn reversal and the pitch up effect of spoiler deflection.

Flex Ruehle’s Comments

I have attached an email from Felix Ruehle with his comments on the report and the incident.

You report is excellent however I think it's hard to see how quickly or slowly everything happened because my experience is that reports from stress situations follow a different clock.

Since hang gliding was born turbulence can be a problem for safe flying. However different developments improved the safety. One of the latest developments is the fixed V-tail with a lifting airfoil from A-I-R. How does it work? The glider is designed to have the same pitch up moment with tail like the standard ATOS with 0° flap.

With thermal, take off and landing flap setting the pitch up moment is significantly higher with the V-tail. Additionally the V-tail increases pitch damping very significantly with all flap settings. Of course instead of a tail the sweep angle can be increased too to get the same pitch damping effect. However this didn't work out as well for the ATOS, because higher sweep in combination with wing bending would cause dynamic problems.

With the V-tail the glider flies significantly more comfortable. In opposite to the opinion of some pilots, that a positive pitch up moment only protects a glider from tumbling, this is not the case. It is a result of several flight incidents with all types of hang gliders and as well with the hang glider drop test made by the DHV a few years ago that even with a certified hang glider it is possible to tumble.

According to my opinion the main parameters are: Pitch damping which can be increased by higher speed and by the wing area distribution in flight direction. For example a higher sweep angle or a tail, increase pitch damping as well as a forward pilot position. Pitch up moment. This is the moment which must be above a certain value for certification. Small distance from aerodynamic centre to CG.

For example a short A-frame is positive. High airspeed in relation to the turbulence is positive too.

The incident

The air was not very smooth this day and there was over development with rain shortly after the incident at this spot. Ron who landed close to help Dave (thanks Ron) hit some strong turbulence too. However, the day wasn't that rough that pilots usually would stop flying.

According to my opinion the tumbling from Dave was caused due to low airspeed in relation to the turbulence. The thermal speed under this condition was already little slow. The reversal turn reduced the speed probably further. This for example is a very good practice in smooth condition, doing reversal with constant speed. Take care: If you don't pull in during the reversal the speed drops.

I flew to the same spot the next day and felt comfortable with about 55km/h (34 mph) as min. thermal speed. This day looked smoother to me as the previous day.

Does the tail improve the safety? At the online contest (olc) 2002 the ATOS is the glider which has flown the most km before any other wing (including flex wing) and the ATOS flew much more km than other rigids, too. Many pilots have flown sometimes under extremely hard conditions and have reported the good behavior under turbulent condition.

It looks to me like active flying is getting more and more important. With the fast gliders the pilots have the possibility to fly with extra speed or high bank angle without losing too much of performance and it looks too me like the ATOS with the new V-tail is a step to improve pilots safety to a very high level even with the incident of Dave.

Under strong condition the glider gets extra stability with high bank angle and higher speed. While doing a reversal you can easily lose speed and the pilot has no extra g loading. I think this can be an interesting discussion how different pilots handle turbulent air.

Discuss "The Spanish ATOS “incident”" at the Oz Report forum   link»

Felix Ruehle

David Cross the pilot involved sent his report to Felix Ruehle at AIR two weeks ago. So far nothing back from Felix.

Discuss AIR ATOS at OzReport.com/forum/phpBB2

Discuss "No word from Felix on ATOS “incident”" at the Oz Report forum   link»

Australia|battery|donations|equipment|Europe|Felix Ruehle|George Stebbins|Oz Report|power|sailplane|sport

George Stebbins <gstebbins@lahd.lacity.org> writes:

I am not really much of a fan of ads, but hey, most folks don't donate/subscribe, so what do they want for free, their money back? I donate/subscribe, but while I don't really like the ads, they do serve a purpose, and if it helps keep the Oz Report coming, well, I'm all for that. Oh, and thanks for keeping them non- intrusive.

Unlike those cowards who don't want you to publish their opinions, you can print mine, including this!

(editor’s note: About 400 people have sent in donations to support the Oz Report. This is a phenomenal number given that we have between 2,500 to 3,500 fairly steady readers, Obviously many of the readers are more casual than others, and feel that they don’t receive enough benefit to be worth the $10 to $20/year that they might sent my way, and of course, this is a reasonable and honorable decision.

One way you can think of ads is that they help make up for the readers who don’t send in donations. Their donations are paid for by the advertisers who want everyone to look at their ads. Of course, even if everyone donated to the Oz Report there would still most likely be ads because they bring in income and because they are reasonable messages from a legitimate part of the hang gliding community.

Hang Glider pilots don’t deserve all the great things that they get from their manufacturers. By “don’t deserve” I mean that our market is way too small, and the financial rewards too small for hang gliding equipment manufacturers to have a viable business if it weren’t for their love of the sport.

Just look at the incredible flight computers that are available to hang glider and paraglider pilots. They are much more compact and use much less battery power than those available to glider pilots. In many ways they are much more sophisticated (although this is not always true) than the instruments used by sailplane pilots. The market for these electronic toys is so small I can’t imagine how they justify the research and development costs.

Then look at all the hang glider development going on in Australia, the US, Europe and the Ukraine. These designers have to love hang gliding to keep working at the low wages they get paid to do this.

I think that if there is any way that the Oz Report can help support the industry, I’m willing to help out. Putting out ads is surely one way to help. Putting out articles with new product announcements helps potential customers and manufacturers.

But, the Oz Report has to be a trusted source of at least one person’s opinion (that hopefully reflects research and knowledge) about the goods produced by the manufacturers. As far as I’m concerned it is, whether the Oz Report displays ads or not.

As one example of this, note that I have written lots of articles (favorable and unfavorable) about the AIR ATOS rigid wing hang gliders. I’m on good terms with Felix Ruehle owner of AIR. I fly the AIR ATOS. But last year my articles stopped all sales of ATOS gliders for a good amount of time. Right or wrong I write ‘em as I see ‘em, and that’s the way it will continue.)

Discuss ads at OzReport.com/forum/phpBB2

Discuss "Ads" at the Oz Report forum   link»

dust devil|Felix Ruehle|harness|Peter Dall|tail|tip wands|tow|towing

Peter Dall <Peter.Dall@casa.gov.au> responds (finally) to my request for his story:

It is always interesting to read how outsiders perceive stressful situations we find ourselves in. My impressions of going upside down at Hay are a little different to what Grant reported (https://OzReport.com/Ozv7n24.shtml)

I had finally gotten around to trying the tail Felix sent me for my ATOS (early model). I wound the nose catch in 2 turns to compensate. Not sure why I did this – probably something I read in the Oz Report ☺ - or maybe something Tony or Johann had told me.

At first I didn’t like the way the glider felt with the tail on.

I found the yaw characteristics of the glider were changed, and I couldn’t do yawing turns like I used to when tightening up in a thermal.

I also found stall buffet to be annoying, in thermalling, and also when pushing the bar out on car tow. This problem was diminished when I moved my hang point forward, or maybe I just got used to flying faster. I guess I was in the habit of flying a bit slow. But I had gotten used to recognising the onset of stall and wing drop, and this was always benign and felt comfortable. Of course I made sure I had plenty of height before slowing right down.

On the second last day of the comp I took the tail off again, and put the nose catch back to how it was before. But now I didn’t like this either! The tail certainly does damp out the pitch twitchiness.

So on the last day I put the tail back on, readjusting the nose catch as before. I was feeling glad that I’d done this, as it was a big day, with huge dust devils. Easily the biggest diameter dusties I’ve ever seen, with dust towing to well over 1000’.

At 1100ft on tow, I flew abreast of one of these monsters, so pinged off, and headed into it. Being big, it didn’t look as violent as some of the small tornadoes. It was rough, but not too scary.

My harness zip kept catching on my pants, so this distracted me, and I was having trouble finding a nice core, but I’d climbed up to around 3000’ in turbulent lift. My team mate called up and said I should come over because he had 1600fpm of very smooth lift. Sounded good, so I opened up my circle downwind and headed over.

The next thing I know, I pitched up, then down over the falls, pointing at the ground with one wing low, but not quite under me. A few seconds later I’m upside down, looking at the sky. I’d always wondered if you could fly a hang glider inverted, and here I was doing it. Nothing seemed to be broken, but perhaps it was time to deploy the chute. I must admit that I found it a bit hard to reach for the chute while hanging on for grim death.

I had only a short time to ponder this problem, when the glider took another wild pitch and did a nice half loop. I came out flying pretty much straight and level. At no time did I lose my grip on the base bar, so when I was upside down I probably only experienced a small negative load. I don’t recall hitting the sail or the A-frame, but I guess the harness back plate supported me wedged in the A-frame.

I don’t know how fast I got up to when pointing at the ground, but I didn’t have the feeling that I might have over-speeded. I wasn’t going particularly slowly when it started. I’m guessing 50-55kph. Certainly comfortably above stall, and basically straight and level. (less than 15º)

I guess I wasn’t too shaken, since I flew back into the dust devil, climbed out to 10,000’, then flew 200km to goal.

I was expecting that this wouldn’t happen when the tail was on. I can only think that my rotation speed would have been a lot faster without it, and perhaps I wouldn’t have been able to keep my hold on the base bar.

I’ve since spent a lot of time retuning the glider. Despite flying back into the dustie, I’m finding that my confidence has been shaken.

It seems logical that the tail should add some extra static stability margin as well as improving the dynamic stability, therefore allowing a bit less washout or a bit less sweep. But I have since been told that I shouldn’t have changed the wing sweep.

(editor’s note: Not necessarily true. See Oz Report interviews with Felix Ruehle published on the first day of the Australian Nationals https://OzReport.com/Ozv7n17.shtml and https://OzReport.com/Ozv7n18.shtml before Peter had his flight.)

I checked my rib angles and adjusted a couple of outboard rib to give more washout. They weren’t perfect, but overall not too bad. One #8 rib was 0.5º low, and one #9 rib was 2º low. I’m still not sure whether to measure these with the sail on or off, or what difference this makes. To put this into perspective, 1º equates to about 1cm at the trailing edge.

My next flight back in Canberra was on a really twitchy day. Looked good with moderate winds, but there was some real awful soup up there at a shear layer that we just couldn’t get out of. I think the storm cells were dropping a cold stream that was hitting the shear layer, and spreading out in all directions. You would be flying along, at cruise, do nothing, and suddenly the glider would stall because of tail gusting. The glider was really spooking me, making me think it was going to go over any second, so I landed after 25 minutes. I was relieved to find that my two buddies also landed soon afterwards because they also found the air unpleasant, and reported similar stalling.

Nonetheless, I still kept thinking that even in shitty air, the glider should make me feel more secure than it did. Back to the drawing board.

My glider is the first one built, so the sail has a few years on it. I have noticed that the outermost seam no longer sits over the #9 rib. I figured the sail has shrunk. Maybe this would also explain why I had suddenly started breaking tip wands, after not having broken one since the glider was built. Also I could never seem to get the trailing edge Velcros to line up, especially over the flap. The top Velcro overshot the lower, almost to the point where they made no contact. I addressed the first problem by sewing an extra piece of Velcro onto each side of the centre zips, effectively moving each sail 2 or 3 cm outboard. Suddenly everything fit perfectly (well after a lot of adjusting), including the trailing edge Velcro (not sure why this would change, but it did).

Subsequent flight testing is encouraging, with the glider now flying very sweetly. Still remains to be seen how I shape up to the big air again next season. One thing I noticed is that the sail strap and rib tension seems to make a lot of difference. Probably more than playing with sweep and washout. Tight is good.

Discuss "Peter’s wild ride" at the Oz Report forum   link»

Alessandro "Alex" Ploner|ATOS|Axxess|Christian Ciech|David Chaumet|Felix Ruehle|John Vernon|Mark Poustinchian|Mike Degtoff|SPAD|Stalker|Tsunami

Ailerons. If one of those rigid wing gliders just had ailerons instead of spoilerons, well then it would just be so much better. Just because it had ailerons. That’s all it would take and if it had them then that glider would be the one, the one that we would all want because it would have so much better performance, because it would have so much less drag.

I mean doesn’t aileron sound so much better than spoileron?

Turned out not to be the case.

If you had a chance to check out Mark Poustinchian’s Stalker web site at http://home.earthlink.net/~mpousti2000/aeros/intro.htm you’ll have been sure to notice the really big item, the fin. The vertical fin. What’s that doing there? Mark really doesn’t say, but I’ve heard the story.

First, it was the V-tails and the floating tails on the other rigid wings to keep them from tucking (we all hope and pray). Then there was the DHV video that seemed to indicate pretty strongly that the ATOS V-tail did a real good job in stopping spins. Now there is Mark building a vertical tail for his Stalker. You’ve got to wonder if it would be a good idea to combine this with a horizontal tail (like the John Vernon’s t-tail OzReport.com/Ozv6n75.htm). You bet it would.

The Stalker suffers from the same problem that all the others rigids suffer from, the relative lack of pitch dampening when compared to flex wing gliders. Because the Stalker has a lower aspect ratio than the ATOS, it is not going to have as small a pitch dampening as the ATOS, but from what I can tell when I’ve flown it, it still has the problem.

But, back to our story. Why is Mark putting a vertical fin on his Stalker? Well, you might remember back when I wrote about Mike Degtoff and his hatchet motion when thermaling (OzReport.com/Ozv6n159.htm). Of course, it turns out that I’m not the only one to notice this exaggerated adverse yaw characteristic of the Stalker2.

The word from pilots in Florida who have been flying with Mark is that Mark’s got the same problem. When thermaling he has plenty of adverse yaw and is hatcheting around like Mike did in Texas at the US Open. Not only that, this motion is considerably reducing his climb rate so that pilots in other rigid wings are significantly out climbing him.

So, the vertical fin. This is Mark’s answer to the adverse yaw problem, and perhaps it is a very good answer indeed. It may solve all the problems that the Stalker2 has with adverse yaw. It may affect the handling of the Stalker2 as dramatically as the V-tail has affected the handling of the ATOS and other rigid wing gliders. It may be as important an addition to the Stalker2 as the horizontal tail is on the Tsunami, and the T-tail is on the Axxess. I haven’t heard yet back from my informants whether things have improved for Mark in this regard. I’ll be there soon so I’ll be able to check it out for myself.

A number of pilots always had a strong skeptical streak about the ailerons only feature of the Stalker as it was proposed and as it was developed. Clearly they were vindicated when the SPADs were added to the Stalker to try to dampen out the adverse yaw. They weren’t enough.

Sure you could learn to live with it and I did. I enjoyed flying the Stalker2 in light conditions and got my timing down so that the adverse yaw didn’t affect my control. But the problem was it apparently affected performance, and Mark won’t stand for that.

I hear that Aeros is working on a Stalker for Mark that will have a longer span and perhaps other changes. This is great news. What we all want is more competition to drive all the manufacturers. Aeros is a great hang glider company and I sure hope that they don’t give up on the Stalker, just because it didn’t work out the first time. Learn from Microsoft on that one.

Of course, the word I also hear from Florida is that the Stalker also doesn’t out glide the ATOS, at 45-50 mph (the range that I’m often gliding in between thermals), but performs just a little bit worse. On the other hand, I hear that there is less bar pressure with the Stalker2 at these speeds than with the ATOS, although I don’t mind the bar pressure myself.

So, I’m sure that Mark is going to do everything he can to have a very competitive rigid wing glider for the Florida cross country season and for the upcoming competitions. Mark’s competitive drive will no doubt be a strong incentive for the Aeros factory.

Oh, did I mention that Gerard will be sending a factory pilot with a Tsunami to the Florida meets? I assume David Chaumet. Christian Ciech is coming and I assume Alex Ploner will also, although I haven’t heard if that is true or not. Felix Ruehle from AIR will be there. Oh, and a few of us local pilots also.

So where does all this talk get me. I’m assuming that it gets the competitive juices flowing and puts the thought in Mark’s mind that he’s going to show that little twerp a thing or two. Yup, I hope that we are all putting it all on the line come this spring in Florida.

Discuss "The fin" at the Oz Report forum   link»

Wed, Dec 11 2002, 12:00:07 pm EST

Davis Straub|Felix Ruehle|Ian Blackmore|Worlds

Ian Blackmore «news» sends in the original XC Magazine article on the Oz Report:

Telling it like it is?

Matt Gerdes profiles Davis Straub, creator of the e-zine everyone loves to hate (but still reads religiously) - the Oz Report

"Push!" "Davis is pushing, number 57 is pushing… again", calls the launch director, sounding tired.

The sound is familiar to the other competitors, Davis Straub fifteen or so places back in line, pushing for the third time this week at the Class 2 Worlds. His strategy is simple; don't let the pilots in front of him waste the best cycles of the day, especially when the site is notorious for blowing out in the early afternoon. Don't let them get away with it, keep it fair.

Davis is the (in)famous creator of the Oz Report, an internet magazine that receives up to thirteen thousand hits per day, and is read by thousands of pilots around the world. The Oz Report has been slandered, and it has been praised, often by the same people.

It has been accused of costing jobs in the industry, halting the sales of some products, and making the success of others. Through it all, Davis has been at the helm, providing hang glider pilots around the world with a source for the freshest free flight news - from comp results to the juiciest industry rumors.

In the summer of 1996, Davis started the Oz Report as a simple newsletter for his friends in the Pacific Northwest, reporting on the flying in Australia (hence Oz).

Fast forward a few years and Davis finds himself deeply intertwined in the international hang gliding community, with thousands of readers expecting something from him and his online mag.

Now, in his own words, Davis wants to "…stimulate the interest of the Oz Report's readers and to not shy away from controversy. I want to stir things up and get pilots motivated to go flying, go to their club meetings, think about equipment, etc. I'm here to energize pilots." And that he does.

Responding to a comment that the Oz Report has taken much fire from people who think its pages have done the industry harm, Davis replies that "they are my best efforts to tell the truth." He illustrates this with a recent incident.

"Last February I reported on my tuck in Australia. I heard from Felix Ruehle [of AIR] that sales of the ATOS-C stopped right after that series of articles came out. They have since recovered. I am always happily surprised at how well Felix takes my criticism, and how he responds with explanations and fixes. This is the kind of interaction that should take place between the press and manufacturers. They should hear the real story from the field, and not some happy made up news that never discusses the problems, and believe me, there are always problems.

Davis continued, "The Oz Report can be, and often is, very blunt. I just don't have the temperament that lets me pull the punches. I am not conflict adverse. My way of getting at the truth is telling the story in a simple and straight forward manner and letting whatever happens happen."

"Rumors?" I ask.

"I label the rumors as such. I want the Oz Report to be fun, and rumors are part of the fun. If someone points out that a particular rumor is false, then I publish that. The thing about an e-zine is that you can be very quickly corrected."

"The Oz Report doesn't take any advertising so it isn't beholding in any way to commercial concerns in the hang gliding community. It doesn't take paid subscriptions, so it doesn't have to please readers in order for me to continue having a paying job. If pilots didn't want to read the Oz Report any more, then that would be okay also. “

"My mission is to be the megaphone, to be the person that yells out that the tree in the forest has fallen. Flying hang gliders has its own intrinsic meaning, but we are also entities that communicate. We get additional meaning from the stories about what we do. We need to have both the meaning of the experience and the meaning of the story or we don't feel the full meaning."

Davis says that he would like the motto of the Oz Report to be 'Without Fear or Favor', although he feels that it is too high a standard to take literally. The Oz Report is a respectable blend of concern and irreverence.

In a recent Oz Report, Davis panned the Icaro 4-Flight helmet, calling it a 'Salad bowl with string.' Davis says that the helmet does nothing to protect the pilot, but reduces drag. The very next day he was wearing one, flying in the World Championships at Chelan. Strange?

No, it isn't a paradox, and there's nothing hypocritical about it. It's just Davis Straub, telling it like it is.

David "Dave" Glover|TV

David Glover <david@davidglover.com> writes:

http://www.reevolution.tv/episodes.php?thisEpisode=11

Showed November 16 and again on November 22 on TNN. Look like a RedBull sponsored TV. Shows in the wee hours on the re-broadcast. Could be time to learn to program the VCR

Discuss "Zapata World Records on TV" at the Oz Report forum   link»

Felix Ruehle|Richard Nikoley|Steve Morris|Vincent "Vince" Endter

Vince Endter <n4nv@pacbell.net> sends this to the rigid wing list:

Felix Ruehle was at Mission Soaring yesterday to give a talk on the aerodynamics, construction and flying of the Atos line of hang gliders, and his new tail design. For the engineering types, he went quite in depth about the aeronautical design of the Atos. With Felix's permission, I am going to make a web page that will cover most of the repair and checks needed to keep an Atos flying safely for many years.

There are a couple of points that I will make now. The 50mph/80Kph VNE is the VNE of the Atos with full flaps. The Atos is truck tested by the DHV to 62mph/100Kph. 80Kph is the same as the yellow arc in an airplane. It should be only exceeded in smooth air. Felix considers 75mph/120Kph to be the VNE of the glider. He cautions that at this speed, it is possible for turbulence to cause the glider to exceed design loads. The same can be said to a too aggressive push out at this speed.

Felix told us of an older gentleman who showed up one day to test fly an Atos. He was about 60 years old and was dressed in a suit. He appeared to be a little frail. Felix waited later in the day for conditions to die down before letting the pilot test fly the glider. He as a little concerned with his launching because it looked like he was a little weak to ground handle the glider.

The fellow had a good launch in flew away. When they arrived at the LZ, he heard stories from the other pilots that this guy did 4 LOOPS in the Atos. It never occurred to Felix that he should tell this guy not to do aero in the Atos, since it looked like he would have enough work just to fly the glider.

The tail Felix has designed moves the neutral point of lift further away from the CG, which improves stability. Unfortunately, we were not able to view the video of the DHV test of the tail due to Felix's tape being in PAL (European) format. The tail does provide lift in flight and the pilot might want to move their hang point back 1 cm to make up for this. He also recommends placing the glider bag in the D- cell to offset the weight of the tail.

I was able to test fly his new tail. I flew my old Atos (Christoph and I put on a new D-cell). I was surprised that the bar still seemed to respond with the same light touch that I am used to. I thought with a fixed tail (especially one that generated lift in flight) would make the bar feel heavy.

It was a normal day at Sled Heaven so I was not able to tell how much the tail dampens the bar in rough air. I did not notice anything different on landing, but Felix says he can feel the tail stall just before he flares. I did some stall entries in flight with the tail and found that I had to push out farther to get the glider to stall. I did not pay attention to my airspeed at the time so I don't know it the tail lowers the stall speed, but it felt like it.

Felix reiterated what I have said in the past about speeds to fly the Atos. Don't fly by watching an airspeed indicator. Fly by bar position. The glider should be trimmed so that the base tube is just below your nose. In rougher air pull the bar in a couple of inches. The closer one hangs to the base tube, the more stable the glider. In Europe where rigids can surpass flex wings in number, the pilots having the most trouble transitioning to the Atos are high time pilots who have been flying 25+ years. They have a hard time not pushing out while flying. There should be very little need to push out more than your forehead in flight.

I was supposed to be flying today but the winds are out of the northeast so I wrote up more from Felix's talk as well as my private conversations with him and Christoph.

One of the reasons Felix came to the US this trip, was to apologize to his dealers about the lack of parts and service from AIR. At the height of production (just before Davis' incident slowed the market), sales of the Atos had reached 12 a week. Soon after the Davis incident the market dropped to two a week. Now that AIR is slower, Felix is trying to get on top of the parts and service situation. While in Northern California he is going to train the people at Mission Soaring how to do a check on an Atos.

In Germany, gliders are required to be certified every two years (similar to aircraft annuals here). During this inspection, all the cables are replaced, new flap and spoiler limiter ropes, some of the mounting hardware replaced. The sails are removed and the spars are inspected. The sails are re-installed and the ribs are checked for proper washout.

Christoph arrived here a couple of days earlier than Felix. He came over my house and I installed one of my 15 minute racks (made from electrical conduit) on his rental car and then we installed a new spar on my old Atos. The new spar was for a C model, so I guess I might have and Atos C-. We performed most of the checks done in Germany. All the ribs were checked and the number 8 was found to be about 2° out of spec. Chris showed me how to change the angle; it only takes about 5 minutes.

I will have pictures of this when I make the web page along with the spec for each rib. I will also show pictures of the wing sweep check. I found out the proper way to remove and replace the sail. It should take only about a minute to remove and 2 minutes to replace.

Even though the Atos is massed produced, it is very much a hand made glider. All the composite work is done with wet lay-up by hand. The spars are made as one piece in a mold, and then cut in half. This helps insure that both spars are the same weight. The spars are made with a foam core, as is the d-cell. Two layers of carbon with a 45° weave are used at the inner spar and one layer with the same weave is used at the outer spar.

The attachment bolts have carbon roving wrapped around them and then extending down the spar. There are 90 at the inner spar tapering to 15 near the tip (I always wondered how they attached those big steel eyebolts to the carbon spar). The spars are made in the same fashion as several European sailplanes. Composite parts are no longer made in Germany (except for prototypes at the AIR factory), they are produced in the Czech Republic and Slovenia to keep the cost down. Felix had no secrets of the design or manufacturing of the glider.

At the AIR factory they will change an Atos to an Atos-C for $1950 euro. I hope that they will train the dealers here how to do the same change. The washout is a little different on the C than the original Atos, less at the inner ribs and more at the outer ones. All the Atos gliders can have the new washout specs.

Some more notes on stability. If too much stability is designed into a glider bad things can happen as well. Too much bar pressure can result and when the nose is popped up this is bad. In Europe this year, a pilot flying a beginner king posted flex wing with lots of stability tumbled when the pilot's nose was popped up and he did not have enough strength to pull it down. The result was a vertical climb to a stall, then tumble.

Tailless gliders are a compromise in stability. During spin testing, AIR and the DHV found that the Atos would not spin more than one and one half turns (this was without the tail) even though the pilot continued with the control input that caused the spin in the first place. The way it spins it self corrects after that. There have been some accidents in Europe as a result of aerobatics. In one case, the pilot fell against the control bar and it broke, then the broken piece punctured the spar, which caused it to fail. There were three Atos tucks in Europe (over a 3 year period) where the glider recovered and the glider flew away undamaged (though there was probably some staining to the pilots harness).

Felix has been working on a version of the Atos where the pilot sits up in the wing. AIR started on the project in 1999. Now that production has slowed down, they might get more time to work on it.

The tails are still considered pre production. The design is finished, but they are still working on the manufacturing and mounting. Currently they are making 4 tails a week. As soon as they feel confident of the process they will increase to 8 tails a week.

Many of the pilots in Europe don't want the tail. Some say the tail makes the glider feel more like a flex wing (is this a good thing?). Without the tail, Felix recommends 0 to 5° of flap when thermaling. With the tail he recommends 5 to 15°. The German comp pilots who fly with the tail are able to fly with less twist in the wing. The drawback to this is you can never safely fly the glider without the tail without changing the twist to its pre-tail spec.

Richard Nikoley <rn@provantacorp.com> responds to the rigid wing list:

Having been there, there's one thing I'd like to mention and that is I really appreciated the attitude of Felix. He's the consummate scientist, just like talking to Steve Morris. He's not going to stand there and bullshit you about what the tail does or does not do. He said flat out that the tail likely will not prevent all tucks, and he doesn't even know if it will prevent any that would have occurred tailless. He also said that a lot of pilots in Germany have commented that they couldn't tell any difference.

So far, all they are confident in is that it provides a smoother ride in choppy air -- i.e., so you're bar is not hunting all over the place -- and that using the same control inputs that cause a spin without the tail, causes a slight wing-over with the tail. When I brought up the video clip we all saw a couple of weeks ago, he was quick to correct me by saying that the video with the tail was _not_ a spin, but was a test using the exact same control input as what put the ATOS in a spin without the tail.

Discuss "Felix in America" at the Oz Report forum   link»

bridle

The clever folks in New Castle have come up with a retractable bridle that works off some pulleys and bungees up in the sail. The line runs through a pulley on the bottom of your keel just in front of your hang point.

After you release from the tow line you undo a snap shackle that connects to your waist line and the bridle line retracts into your sail. I’ll have pictures soon that will give you a better idea of how it works.

Discuss "Retractable bridle" at the Oz Report forum   link»

Christof Kratzner|Felix Ruehle|Joe Greblo

Felix Ruehle <felix_ruehle@yahoo.de> writes:

Christof and Felix have just arrived in SF. We will have a pilots meeting for all pilots at Saturday the 16^th 9:ooam at Mission Soaring Center. Subjects of the meeting are:

- all about the last version of the ATOS with V-tail.

- maintenance: we will forward all our experiences from rigid wing checks

- spins and tucks

- landing and take off technique

- if possible, we will shorten the program in order to go demo flying (weather forecast looks good) detail information phone 408.262.1055

Further A-I-R meetings are next weekend in LA and San Diego. We will have ATOS aerotowing demos, even for those without a tow rating. Pilots may qualify by getting a tow lesson the same day.

For detail information please contact Joe Greblo (<windsports@earthlink.net>)

Those who like to meet christof and felix during next week on the way down to San Diego, can contact us under <felix_ruehle@yahoo.de>

Discuss "Felix in America" at the Oz Report forum   link»

Felix Ruehle|racks

I’ve always had a concern about putting any dents in my ATOS from carting it around on the truck. In the first place it just seems like a terrible thing that this could put dents in your glider. And secondly, I am still uncertain of what is means to the structural integrity of the glider if I get any dents. I’d just like to be able to avoid the whole issue.

Now, of course, hang glider pilots are use to flex wing gliders that don’t get dents that often from riding around on top of their owner’s trucks. I really don’t know just how much more resistant to denting aluminum is compared to carbon fiber foam sandwiches, but I presume that there is a difference.

On the other hand, just how resistant to denting are sailplanes. We don’t throw them on the top of our vehicles, and we do put them in specially designed trailers with form fitted padded racks that keep them from getting damaged. Still they do seem to be more resistant to denting than the ATOS and other gliders like it.

Gerard solves this problem with the Top Secret by foregoing the foam layer and just building his leading edges out of carbon fiber (at least I think that is the only material in them). This means than you can push in the leading edges with your thumb, but they bounce right back.

I’ve been carrying my ATOS all around the country on top of my truck. Two contests in Florida, drive off to North Carolina, and then to Zapata for the WRE. Drive up to Chelan for the Worlds and then back to Big Spring, Texasfor the US Open. A lot of miles with the ATOS up on the rack.

The rack is flat and has about ½” of dense blue foam and is about four inches wide on each of the four members.

Before the US Open I checked out the leading edges and found only the slightest bit of denting on one leading edge. It was very shallow and took me a long time to notice it. I was very happy with how things were going.

After the US Open I inspected my leading edges once again, and noticed that I had a couple of areas with deeper dents. I was not happy, even those these dents were still quite sallow, about ⅓^rd of the depth of the foam.

Any dents concern me and I wanted to do the right thing, the thing that would assure me that the glider was as strong as possible. I wrote to Felix Ruehle at AIR and asked him whether I should repair these dents. I sent along high resolution versions of the digital photos that I took of the dents.

Felix wrote back:

If there are no cracks in the fibers (and in the pictures it didn't look like there were any) and if the area around the den is not soft then there is no need to repair these dents. Such small repairs are often "repaired" on sailplanes by heating with a hair dryer. I don’t recommend that you do this because the resin and foam can be damaged by the heat and besides unlike on a sailplane the small dents are covered with the sail.

If the area has a big soft spot the upper layer has to be removed together with the foam. Then you can check the lower layer which usually has no damage.

To make a repair replace the volume of the foam with microballoons in epoxy and then this with two layers 160g/sqm with 30mm overlap each.

The dents look like they can be from the edge of the rack when loading not while transport the glider because the glider when transported will usually lay at the spar caps. Another possibility is when the glider is laid on the ground there was a stone and no pad or harness was used to support one side of the glider.

I did check the dented area of cracks in the carbon fibers and for soft spots (using a quarter and tapping the area). I didn’t find either, so it appears as though these dents are minor.

The dents were not above the spar cap, so it didn’t look like I had any damage there.

Felix wrote:

I have tested the spares with strain gauges at different angles of attack. The stress at the spar caps and spar is between 3 and 5 times higher than on the rest of the leading edges. You have some small tolerance for damage in the skin but not on the spar caps or spar wall.

It is most important is to check the corners of the spar wall. You have an extra glass layer there which makes it easy to detect cracks there.

Felix sent me a couple of carbon fiber and foam pads that can be used to support the ATOS while in transport. I lost one in Australiain January but I still have one that I use. Wherever I have used it, there hasn’t been any damage. Felix is going to send me two more of these pads so that I can test them out in Australia. I will publish pictures and send out a report on what I find out.

Discuss "Rack damage" at the Oz Report forum   link»

Thu, Aug 15 2002, 6:00:03 pm EDT

carbon fiber|Felix Ruehle|Scott Rutledge

Quite a while back we published on-line the carbon fiber repair manual originally put together by Scott Rutledge with pictures that he took of Flight Design’s Felix Ruehle (then) and Joseph Stellbauer’s work. The workshop happened in Ellensburg, Washingtonand we all had a great time.

There is a new version of the carbon fiber repair manual up at http://groups.yahoo.com/group/RigidWing/files/
Carbon%20Fiber%20Repair/FD_GB_Repairs.doc.

I‘m sure that you can also find it at www.flightdesign.com.

Sat, Jul 27 2002, 5:00:00 pm EDT

carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane

carbon fiber|Felix Ruehle|John "Ole" Olson|Manfred Ruhmer|Ron Gleason|sailplane

(?-i)John "Ole" Olson|carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane

carbon fiber|Felix Ruehle|Manfred Ruhmer|Ron Gleason|sailplane

There has been some discussion on the rigid wing list lately about the strength of rigid wing hang gliders. I decided to ask all the rigid wing hang glider manufacturers just how strong their gliders were. I sent out a version of the following message to AIR «info», Icaro «staff», Flight Design «flightdesign», Joseph Guggenmos «Drachenbau.JGuggenmos», La Mouette «lamouette», and Aeros «aerosint»:

After Guenther's broken wing in Chelan there is renewed interest and concern regarding the strength and flexibility of the ATOS (and other rigid wing) d-cells. I have previously forwarded to you some of those concerns.

ATOS pilots and others would like to have the assurance that their wings are as strong as they need to be to fly in any of the conditions that we would reasonably expect to encounter in competition and cross country flying. While I'm sure that the answers that we are looking for can involve long and detailed study and explanation, perhaps we can start off with a few basics.

First, the published rating for the Swift Light is Maximum load +6/-4 g, tested +8,7/-6 g. While it is unclear whether this is design load or ultimate load, perhaps you can provide us with the rating for the ATOS-C.

Second, do you use a 50% safety factor to differentiate between design load and ultimate load?

Third, do you design the ATOS to meet JAR 22 specifications?

Fourth, describe the construction of the ATOS spar and d-cell particularly with respect the sparcaps and how the spar is made to operate like an I-beam, if this is in fact the case.

Fifth, there appear to be at least two versions of the ATOS, single and dual place. How much stronger is the dual version and how much stronger would a version be that added about 5 kilos of optimally placed carbon and resin to the single place version?

So far I have received answers from three manufacturers, AIR, Icaro, and La Mouette. I got the following from Felix Ruehle at AIR:

I really appreciate that you are working on this because I think many people are concerned. Still it's not clear to me why Günther’s ATOS broke and there are a few different possibilities. Yesterday, I heard that Günther’s transport box had been damaged with a fork lift when the glider was shipped to Chelan. I expect to get the parts including box back within the next days for further investigations.

The Stratos is tested to a load of about +8900N (ultimate load) and about -4600N, on the DHV test rig. Considering the lower span of the Atos, this is equal to a load of approximately 9200N. According to the DHV requirement, the ultimate load must be higher than hook in weight of the pilot + half the weight of the glider multiplied with 6. This is equal (approximately) to a 6g load positive. Negative, the multiplication factor is 3. The Atos is certified to a maximum take off weight of 150kg.

To clarify what Felix wrote I asked him:

Okay, just to be clear the ultimate load (the load to which the ATOS is tested) for the ATOS is: +6g/-3g?

The design load of the ATOS is +6g/-3g?

It would appear that the Swift Light is static load tested (not on the rig) to 8.7g and -6g. Has the ATOS been static load tested? Results?

Felix wrote:

It's better to compare the maximum load where the glider was tested and how it was tested. For example, the whole glider on a test vehicle or only the spar. If you take Günther’s weight and the maximum tested load, you will get about 10g (don't know exactly how much ballast he had). If you have the total loads it's easier to compare the gliders. Then the pilots have an idea to how many g’s this corresponds to.

The JAR 22 specification is +4g and -2g with an additional safety factors of 1. 5 and 1.15 (for composite materials). The ATOS-C almost meets these requirements. The JAR 22 requires testing at 54 °C and the wing has to hold the load for 3seconds. The Atos is designed for these loads, but it is not tested at 54° C because the DHV test is on a car outside. The resins used in the ATOS are the ones used in sailplanes as well. The Atos spar's are tempered at higher temperature than sail planes in order to resist higher temperature.

I asked:

The JAR 22 specifications would be 6g/-3g before the consideration of composite materials, and 6.9g/-3.45g for composite materials. The ATOS meets the JAR 22 specification if we don't consider the additional factor for carbon fiber?

Felix wrote:

The Atos is certified up to a total take off weight off 150 kg. According to my calculation this is equal to about 7.2 g (tested load) and meets the JAR 22 in this case. With a hook in weight of 100 kg it is about 8g and with a hook in of 80 kg it is 9.7g. The g loads are calculated and not tested in flight. It's better to compare the ultimate strength. Because there are different ways to do the calculation, I would suggest comparing ultimate loads.

Upper and lower main bolt fix the wing. These bolts are fixed with carbon fibers which are wound around the bolt. These fibers (spar caps) are located at the very top and lower side of the spar and are tapered out to the wing tip. Between the spar caps is the spar wall, which takes shear and compression loads. The U-spar is fixed with a skin (C section of the wing) in order to get a D cross section which takes the torsion loads. Spar wall and skin are manufactured with a foam sandwich in order to avoid buckling.

The Atos is designed with approximately the same keel and a similar lay up to the Exxtacy. The inner spar is additionally reinforced. While the Exxtacy will usually fail (at load test) at the spar connection (the nose rings), the Atos spar will fail between rib 1 and 2.

We worked on a tandem version and produced prototypes with higher strength, but there is currently no tested tandem version on the market. Since May of this year the Atos has an additional glass layer at the spar wall which works as a damage indicator but with only a minor influence on strength.

When I asked Icaro about the Stratos, Saskia wrote:

The Stratos has the same structure and parts as the Atos, except for small details. Also for the future we will continue the cooperation with AIR for all the new developments (and we pay a royalty for every Stratos we sell). I am convinced that Felix is a very good engineer and with the trio Felix, Christian and Manfred we will make exceptional and safe wings.

I think that you asked the same questions to Felix, so you can use his reply for both rigid wings.

My response to Saskia was:

I thought that perhaps that Icaro might have specified a slightly different version of the ATOS d-cells. Felix made the unfortunate statement here in Chelan to Ron Gleason, theUSteam leader and ATOS pilot, that, "AIR could make up anything you like in a d-cell." He also said that Alex's ATOS-C was stiffer than other ATOSes with more carbon fiber to keep the leading edges from bending at higher speeds and thereby keeping the trailing edge tighter. I thought perhaps Icaro might have such a version on their Stratos.

Gerard Thevenot wrote:

Adding extra kilograms to a wing already designed, tested and certified might be dangerous, concentrating stress on some points and stiffening the wing thus not absorbing any more the turbulences and shocks.

Actually on my next design I would like to taper my leading edges even more to have a better stress repartition (+ saving weight and handling).

The TOPSECRET has been tested to 840 KG positive and 420 negative without failure. But, again, I would rather fly a rubber glider tested at 2 g's, but unable to reach them, than an undeformable glider tested at 10 G's.

Ultimate load: Carbon has very different mechanical characteristics from metals. It practically does not permanently deform before 97 % of its failure limit.

I am not familiar with JAR22 as I think it is related to standard aviation and our hang gliding landing gear would never pass the specifications.

As far as I have been able to see, our leading edges are quite different from other manufacturers.We are using a main spare for vertical flexion and the front skin for horizontal flexion and torsion.

I have asked Gerard some additional questions and will publish those answers when I get them.

I will have additional articles on this issue and hopefully other responses from manufacturers.

Mon, Jul 15 2002, 5:00:00 pm EDT

Akiko Suzuki|Alessandro "Alex" Ploner|carbon fiber|Chelan|Christian Ciech|Douglas Pohl|dust devil|Felix Ruehle|Gene Matthews|Hansjoerg Truttmann|Icaro 2000|photo|Worlds 2002

http://www.elltel.net/peterandlinda/2002%20Worlds/Worlds%20Main.htm

I guess the meet organizers want to get a few folks into goal. It was looking bad that Kari was the only women to make goal so far. The women got the little task of Withrow, Mansfield and back to the airport.

The rigid wing pilots were sent to Farmer, Sims Corner and back. The Swift pilots had an additional turnpoint near DryFalls. At least 58 pilots made goal today out of 82 pilots. Now people can worry about how fast they flew.

Today was a very good Chelan flying day. Absolutely blue. Lift predicted to be 600 fpm, and actually we got up to 900 fpm to 9,000’ which seemed to be right also. 50 degrees at 9,000’ which is a little cool if you have on what you wore in Florida. Winds out of the west predicted to be between 5 and 10 mph, which again was about right.

It was a bit scratchy at launch for some people. Kari was down on the last ridge before the soccer field. She just had to contrite on getting up. Lots of pilots were near or just below launch for a few minutes before they slowly worked their way over the butte and into the good lift. We go to 7,500’ before heading out to the flats where we could see some fields filled with dust devils.

The women were launching between the rocks, and the rigids were heading off Green Monster. I’ve never seen Green Monster so peaceful, with it coming straight in at about 5 mph. Beautiful and fun to launch in.

We gaggle up north of power lines on the flats and just stay at 8,600’ waiting for the later start clocks. Almost every one launched early because they weren’t sure that everything would remain copasetic on the butte. Now we had time to kill in the cold air. The start window opens at 2 and stops at 3 PM.

A few pilots head out at 2 and 2:15. I and some others take the 2:30, and others wait for later clocks. The idea is to fly fast using the dust devils and make sure that they don’t catch you. Hard to do.

The great Chelan air has returned, with little effect from the high pressure. The thermals at indeed 6 to 700 fpm and you can climb right up to the 8,000’ inversion before it slows down. As the day wears on it gets better and better with smoother and more plentiful lift, and warmer air.

This is a race, not a contest to see how far you can fly into the wind. The idea is only climb in the strong stuff. A lot of pilots show up at the Sims Corner turnpoint, so I’m in a mood to race as hard as possible back to the airport.

We’ve got to make it to the rim and then dive fast down to the airport to get down to 1,500’ over the airport or the goal keepers will have difficulty getting your goal crossing time. (More on this later.)

Of course with all the pilots diving into the airport we’re hoping that not too much general aviation traffic comes in. There is some, but we work our way around it.

I think Johnny Carr flew after they patched up his Swift Lite. I saw a lot of carbon fiber curing in the sun on top. There are two Swift factory reps here working with the pilots. Felix Ruehle is also here helping out all the competitors flying AIR ATOSes. It is so nice to have factory support on the butte.

I don’t have any real results yet today as I have no idea when pilots started. Francoise Mocellin was in after Kari. Then Natalia Khamlova from Russia, Gudrun Maier, and Francoise Dieuzeide.

Japanese pilot at the parade

Results after two days:

USWomen are in first

US Class 2 team is in first

US Class 5 team would be in first except for an action that is currently under protest. Otherwise we are in second. All team results are up on the web at the URL above.

Douglas Pohl «dpohl» sends in this URL for Worlds pictures:

http://65.187.85.53/aviation/dir_hg/dir_chelan/20020714_
World_Cham pionships/800x600/index.htm

Gene Matthews «skydog63» writes:

People watching at the combined Women's and Men's FAI World Championships in Chelan Washington,USA

http://photos.yahoo.com/bc/skydogb/lst?.dir=/WORLD+
MEET+PEOPLE&.src=ph&.order=&.view=t&.done=http%3a//
photos.yahoo.com/bc/skydogb/lst%3f%26.dir=/WORLD
%2bMEET%2bPEOPLE%26.src=ph%26.view=t

Thu, Jul 11 2002, 5:00:02 pm EDT

Christian Ciech|Felix Ruehle|Florida

Quiet glider, quiet mind.

Today Felix Ruehle put his new V-tail on my ATOS-C. The glider now feels rock solid. No longer does it move around in pitch. I’m astounded by the difference.

He also decreased the sweep by two turns or about 2.7 cm. This required a slight loosening of the trailing edge straps. Also he moved my hang point back about an inch, which proved to be an incorrect move, as I now trimmed at about 25 mph. I have since moved the hang point back to the original position (the factory location).

It is hard to belief that these changes have made such a dramatic improvement in the feel of the glider. I have only flown it for about an hour and a half, so there is a lot of testing yet to do, but if this is any indication of what these change bring about, then I’m sure many ATOS pilots will be asking for them.

Lately (well, since after the Floridameets) I have been very aware of any unbidden pitch and roll movements in the ATOS-C. I can feel everything. The fact that the glider now feels rock solid is unbelievable given how it felt yesterday.

Yesterday I wondered how I was going to be able to compete. Today I feel that I have at least a chance to be competitive.

As Felix was working on my ATOS-C, Christian Ciech came over to ask Felix about getting a V-tail. It seems as though Christian did not like the feel of his STRATOS on the fourth day in Chelan (at least on that day) and this may explain why his landed early.

The V-tail is fixed in position, i.e. it is not floating. It is a lifting, unsymmetrical wing.

Pictures soon.

Alessandro "Alex" Ploner|Alex Ploner|André Wolfe|Bo Hagewood|David Glover|Felix Ruehle|Glen Volk|Jamie Shelden|Mike Barber|paraglider|Pete Lehmann|Timothy Ettridge|World Record Encampment 2002

Dark skies cover central Texas as we drive up north along our normal flight route (except for highway 55 which is still closed after flash floods) from Zapata to Big Spring. It is just amazing that we can fly this far in a day in a hang glider. You have to drive all day to get here – 500 miles by the highway.

Jamie Sheldon and Alex Ploner left just before we did this morning on their way to San Francisco to pick up Felix Ruehle and then head for the Worlds in Chelan. We are on our way directly to the Worlds and have to leave the WRE behind.

It is with great disappointment that we abandon our friends and fellow pilots in Zapata, especially after eight days of stratus clouds, cu nimbs, and rain. With the weather forecast not especially encouraging (although the winds look good), and the high probability of very excessive moisture in the ground along our projected route, we bail.

There is over a week left in the second session and David Glover has already volunteered to extend it four days at no additional cost in what appears to be a vain attempt to try to capture some reasonable weather. I feel terrible about the pilots who have come for the second session, and not all that good for the ones who came for the first but missed the big day.

When we got up this morning it was the grayest and darkest we’d every seen in Zapata, looked like Seattle. We’ve had the over run with low cumulus clouds come in early and turn the sky dark, but these clouds were higher and didn’t indicate any heating from the ground.

As we traveled north these clouds accompanied us until we got to Sterling City, where a cu nimb swallowed these clouds and dumped heavy rain on us as we came into town. Even if you could have flown from Zapata, you would have landed at 350 miles out at the edge of the cu nimb. Of course, even that flight was not possible today.

We saw lots of standing water out in the desert as we passed through Carrizo Springs, as well as many signs of flash floods well into the hill country. The federal government has agreed with the state and named Uvalde County a disaster area, along with a number of other counties.

The local disaster warning radio came on and warned of strong rains and flash floods near San Angelo as we passed by to the west a few miles. Already seven people have been killed by the floods.

I feel a great deal of responsibility for having encouraged so many pilots to come and fly in the WRE. I was basically guaranteeing them a 200-mile flight on almost any day. That promise was completely washed out by the conditions that we encountered this year. Not just the rain, but the lack of winds for the week preceding the rain.

Two weeks ago we had two paraglider pilots signed up for the second session. Now there are ten at the WRE all drawn here by the fact that four paraglider pilots broke the current world record on two days during the first session. Days that were not considered to be all that great.

I don’t feel that I led the paraglider pilots astray, after all I can’t imagine that paraglider pilots pay any attention to anything I write, but I do feel sorry for the three French and two Italian pilots (along with two drivers and a cameraman) you came so far on such short notice.

Soon after the four of us bailed, most of the hang glider pilots bailed also. Glen Volk who flew in to Zapata last night broken down his glider and was about to fly back home (but I think he may wait one more day). Andre Wolf came back on the same plane as Glen from San Diego, but saw how bad it was in San Antonio and didn’t even set up his glider. David Glover says the French paraglider pilots are in open revolt (whatever that means).

Mike Barber, Pete Lehmann, and Bo Hagewood are still hanging in there. It looks like the whole California crew has headed for Hobbs, NM, and Prior and Judy Powers decided to drive back to Florida (where it is really really raining). I sincerely apologize to all these pilots for giving everyone the idea that Zapata was an absolute gimme and that you just had to show up for great things to happen.

Sure, a big flood like we’ve had was totally unexpected (but aren’t they always?). I felt and wrote that the summer high pressure weather pattern was so strong and consistent that essentially nothing could get in its way. How wrong I proved to be.

I sure hope things turn around soon, that the ground dries out, and that those pilots left to fly in south Texas get a chance to go for the record.

Will I be back in Zapata next year? If I still want to go 500 miles, you bet. There is no place in the world like it and I think that there will be plenty of chances next year to go very very far. There still is plenty of time to go far this year in July and August as Texas dries out (which it should).

The next stop in Texas after the Worlds in Chelan is Big Spring (which at the moment is fairly dry). The rains occurred almost exclusively to the south.

The San Antonio paper reports that the low over central Texas has become detached from the regular upper level flow (I assume they mean the jet stream with west to east flow) and is wobbling around central Texas without a sense of direction. It keeps pumping in moisture from the gulf which feeds the rainfall.

When it was raining a few days ago in Zapata. Photo by Timothy Ettridge

Discuss "WRE – disappointment/dispersal" at the Oz Report forum   link»  

Alessandro "Alex" Ploner|Alex Ploner|Doug Prather|Felix Ruehle|George Ferris|Jamie Shelden|Mosquito|World Record Encampment 2002

Some flying today, but no record attempts as the moisture still hangs heavy in the sky. Strong winds – 30 mph – which is what we love. No real rain and little over development.

It is drying out and we expect better flying as the week proceeds.

George Ferris left today headed from Chelan for the Worlds. Jamie Sheldon and Alex Ploner leave tomorrow so that they can pick up Felix Ruehle in San Francisco on Friday and then get up to Chelan.

Doug Prather flies his Mosquito as Zapata:

Discuss "WRE – oh so very very patient" at the Oz Report forum   link»  

Aeronautic Innovation Rühle & Co GmbH|Felix Rühle|Felix Ruehle

www.a-i-r.de

Felix Rühle «felix» writes:

We checked all the ATOSes that we have access to and found that the spoiler rope was fine. Some of the Atos that we checked had more than 200 hours on them. I know of one incident were the spoiler rope broke. In this case a different spoiler lever was used on a prototype.

The rope, which is attached at the spoiler, goes around the pulley at the rib and then straight to the other pulley at the spar. In this case the rope was not straight there and was wound around the spoiler lever. Because this was not checked before flight the rope broke after a one hour flight at the spoiler lever.

On the new Atoses or when doing a checkup we replace the existing rope with a dyneema rope which is much stronger and add a bungee which keeps the spoiler rope tight during transport. With this change you have a little better chance if the glider is not set up correctly and the spoiler rope is not checked.

We had another incident with an Atos C. One spoiler rib was not attached. Because the Atos C would go level after a few turns the pilot decided to land, which worked.

Tue, May 7 2002, 12:00:01 pm EDT

Alessandro "Alex" Ploner|Christian Ciech|Felix Ruehle|record|Worlds

Alessandro "Alex" Ploner|Christian Ciech|Felix Ruehle|record|World Record Encampment|Worlds

Alessandro "Alex" Ploner|Christian Ciech|Felix Ruehle|record|World Record Encampment|Worlds

Alessandro "Alex" Ploner|Christian Ciech|Felix Ruehle|record|Worlds

www.flytec.com

Pilots who are coming to the USto fly in the Worlds in Chelan might consider going to the World Record Encampment in Zapata before hand. Just it is a bit out of the way, but it will give you a great opportunity to set a world record. Felix Ruehle is hoping to be able to send Alex Ploner and Christian Ciech has won a WRE expenses paid trip to the WRE.

First session June 15-28, 2002,
Second session June 29 - July 12, 2002

Thu, May 2 2002, 3:00:01 am EDT

carbon fiber|Felix Ruehle|Ghostbuster|Mark Poustinchian|Quest Air|record|Ron Gleason

Mark Poustinchian «mpousti2000» writes:

Yesterday Ron Gleason and I decided to set a 120-mile triangle task and try to set a new East Coast record from Quest Air. The first turn point was to the NW over the big Dunnellon airport. The second turn point was NE of lake Weir overOcala national forest and then back to Quest Air. It started out like mission impossible on the first leg. We could hardly stay above 2000’.

I towed first and was a couple miles away from Ron. With the massive sink between the thermals and lack of altitude, I needed some help to spot thermals, however Ron got low and I had to keep going or sink out in sink pockets. We survived, however Ron got further behind and I decided to get going alone while the going got better.

About 10 miles from Dunnellon the conditions improved and we were able to get over 4000’ agl. By the time I was to the first turn point Ron was low about 5 miles behind and very low. He had several low saves from 500’ agl. The clouds were getting big and I was afraid that we may not be able to finish the task due to thunder storms.

I was getting over 5000’ agl on the second leg and started to let go of the breaks and flew much faster. The second turn point was difficult due to lack of landing zones. So I made sure to get high enough to make it before heading south to Quest Air. By the time I was over the second turn point I had the anticipated conversion zone all the way to back to Quest Air.

Big clouds were lined up and they actually started to look a little scary. I worked a thermal very close to the last turn point over Ocala National Forest and after that I made a total of 10 turns while I glided 40 miles back to Quest Air. I counted the turns on my track log. The last leg was very fast because I was having trouble with too much altitude. I had to get around some big clouds so that I could see where I was going. Too much lift and big dark clouds made me stuff the bar more and more on my ATOS with the beautiful new sail, new spoiler system and new carbon fiber tips.

By the time I was about 10 miles away from Quest Air over 5000’ agl, Ron was getting close to landing and landed by Lady Lake about 25 to 30 miles away from Quest Air. He watched the thunder storms develop and got a good dose of rain. I got over Quest Air about 3500’ and landed before the rain after 4 hours and 45 minutes of flying.

I lost my recorded points from the start on my eMap GPS. Unfortunately I can’t set the time for recording on this GPS and it is only good for the last few hours of a flight. However, the only part that I lost was ½ of the first leg.

My ATOS flies so much better now and I absolutely love the performance, speed and it’s sweet light handling. I did a little X-C flight with another great X-C pilot (a possible USA World Team member) on the new ACCESS+ and now I am convinced that the ATOS is the glider that I want to fly.

When this pilot and I were flying GhostBusters, I didn’t have a chance on glide when I was gliding with him. This was due to his built in ballast, but now with me on the ATOS and him on the ACCESS+, it is a different ball game. I want to thank Felix Ruehle and Christoph from AIR for putting the new sail on my glider and doing the upgrades.

Now, the new records are well within reach. I don’t do the comps because I hate gaggle flying and I want to be on my own and love the low saves and crossing the big blue holes and going far with my ATOS. I am also working on a great hang gliding screen saver for AIR and it will be ready for free down load soon.

Sun, Apr 21 2002, 4:00:02 pm EDT

Christian Ciech|Felix Ruehle

I spoke with Christian Ciech quite a bit about the Icaro Stratos. There are two versions – one based on the ATOS with the WW control frame. The other based on the ATOS-C. Christian has slightly modified the ATOS-C for his Stratos for this contest.

The modifications consist mainly of a longer tip wand and a longer sail (last panel) to accommodate the longer tip wand. The longitudinal sew line for the sail is on the bottom not the top like on the ATOS-C. This allows for them to change the color pattern. The ATOS-C changes the sail cloth at this line, the Stratos uses the thinner sail clothe all around. There are some slight changes in the sail cut.

Christian is doing very well on his Stratos, but then he is a very good pilot also, a former member of the Italian flex wing national team. Today he was gliding very well, we’ll see if he keeps that up.

Icaro bills Christian as the designer of the Stratos. After my inspections here, I would say that this is marketing hyperbola. Christian has been involved in making modifications to the ATOS-C to his liking. Felix Ruehle is the designer of 99% of the Stratos.

Felix Ruehle|Gerolf Heinrichs|Steve Pearson|Wallaby Open 2002|weather

The forecast for Sunday was for 60% chance of rain. Given the premature calling of the day by the safety committee on the first day, we are committed to flying if the weather will permit it. We are also committed to maximum flexibility so as not to call the day before any pilots get in the air if it looks possible.

Unfortunately the rain comes in strong as though it was June or July. Huge cu-nimbs form and it dumps big time. The task committee finally calls the day at 2 PM. Maybe tomorrow, maybe Tuesday.

Tonight we will hold the discussion with Steve Pearson, Felix Ruehle, and Gerolf Heinrichs on aerodynamics of flex wings and rigid wings, especially with respect to the DHV pitch test, tucks, and tumbles.

Wallaby Open scores will be found at: http://www.elltel.net/peterandlinda/Wallaby_Open_2002/Wallaby.htm

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Sat, Apr 13 2002, 5:00:02 pm EDT

Alessandro "Alex" Ploner|Felix Ruehle|weather|Worlds

Alessandro "Alex" Ploner|Felix Ruehle|weather|World Record Encampment|Worlds

Alessandro "Alex" Ploner|Felix Ruehle|weather|World Record Encampment|Worlds

Alessandro "Alex" Ploner|Felix Ruehle|weather|Worlds

Felix has made quite a few changes to the ATOS to come up with the ATOS-C. The tip of the sail was extended to cover the tip wands, but at the same time it reduced significantly the amount of air that would escape out the tips. The additional material at the trailing edge and tip increased the sail area at the tip of the glider which has an effect on ATOS-C handling and performance in addition to the effect or reducing the drag by covering the end of the tip wand.

In addition he changed how the Velrco is sewed to the trailing edge going from two seams to one, which brings the trailing edge to a single line instead of a flat 1” wide seam. This changes the shape of the sail to give it a more aerodynamic shape. All these slight changes have significant effects on the ATOS-C safety, handling and performance characteristics.

There are six new ATOS-C’s here at Wallaby. They will be staying in the US. Alex Ploner, the World Champion will be flying one at the Worlds in Chelan in July, and perhaps in Zapata at the WRE. They have been changed from the ATOS-C that I had in Australia.

The sweep has been slightly increased (by about 4 cm as measured along the keel) which increases the pitching moment. The pitch pressures are light enough to handle this pitch moment increase. According to Felix, pitch pressures increase until you reach about 70 kph and then remain constant to 120 kph (this is well beyond VNE). The ATOS-C is reported to be much steadier at 120 kph than the ATOS.

The twist for the ATOS-C has been increased relative to the ATOS. The angle of the ninth rib is now 7.7 degrees up.4 degrees from 7.3. The pitch curve of the ATOS-C is quite a bit above the requirements needed to pass the DHV pitch test, and quite a bit about the ATOS pitch curve.

Felix has been recuperating over the last year and a half from smashing his knee cap acquired during a failed launch attempt. He is also recuperating from the failed operation that put the knee cap back together incorrectly. He is going to be flying at the Wallaby Open (if the weather improves), but he is still concerned about his knee (although he’s walking around just fine).

If he comes in to land in a light wind condition, he’ll be landing on wheels on his ATOS-C as pictured here:

Thu, Apr 11 2002, 6:00:00 pm EDT

Felix Ruehle|Florida

Campbell Bowen|Felix Ruehle|Florida

It rained quite a bit this afternoon in central Florida. Pilots were getting a few quick test flights before the meet. Looks like rain tomorrow – the start of the Wallaby Open.

Spoke quite a bit with Felix Ruehle about the ATOS-C. I’ll report in the next Oz Report. Campbell Bowen flew in on a Flight Design Axxess+ yesterday and left the glider tied up. It’s raining right now.

Fri, Apr 5 2002, 6:00:06 pm EST

Aerodynamics|Felix Ruehle|Gerolf Heinrichs|Rob Kells|Steve Pearson

Gerolf Heinrichs and Felix Ruehle have agreed to make short presentations on the aerodynamics of hang gliders just before the start of the Wallaby Open, or on a day that gets blown out during the meet (if that happens). Then the floor will be opened up to discussion and questions. Steve Pearson will be here, as well as Rob Kells, and many other knowledgeable pilots so I’m sure that we can get a free flowing discussion.

I’ll report on the results of any of the discussion, so that Oz Report readers won’t miss out.

Tue, Mar 12 2002, 12:00:00 pm EST

Felix Ruehle

I reported yesterday that the ATOS-C like the one I was flying in Australiafailed the DHV pitch test. As reported it failed it at 40 km/h or 25 mph. I tucked while going 36 mph. So this particular failure of the DHV pitch test doesn’t tell us much about why the ATOS tucked.

I have an article from Felix Ruehle that I am currently editing and hope to publish tomorrow.

Angelo Crapanzano|parachute|Rob Kells

I had an opportunity to speak with Rob Kells about parachutes at the recent USHGA BOD meeting. Rob admitted to the fact that Wills Wing hasn’t done a good job getting out useful information to pilots to help them pick a parachute of an appropriate size. One problem he mentioned was that there was a wide scatter in the drop test data, the results of tests that determine the rate of fall under various loads.

He has decided that it would be a good idea to publish all the data so that pilots can see just how wide a variation there is in manufacturer’s tests when they report how well their parachutes due.

What should pilots be interested in? For one thing, they will want to know just how fast they will be coming down (given their weight and a portion of the glider’s weight) and how that value relates to their chance to suffer from injury. Of course, if you’re going down under canopy in 500 fpm sink, it’s going to hurt a bit more.

Angelo Crapanzano has presented some strong arguments for his position of chute size and I look forward to hearing more from Rob.

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Sun, Jan 27 2002, 10:00:05 pm EST

Christian Ciech|Felix Ruehle|Gordon Rigg

Christian Ciech|Felix Ruehle|Gordon Rigg|John "Ole" Olson

(?-i)John "Ole" Olson|Christian Ciech|Felix Ruehle|Gordon Rigg

Christian Ciech|Felix Ruehle|Gordon Rigg|John "Ole" Olson

Gordon Rigg«Rigg» writes:

Christian's flex wing glider was incorrectly rigged. Christian told me this himself. Christian flew this whole flight with the undersurface centre zip open. He knew it was open and chose to continue. He then ended up flying through the gulley between two mountains in quite a turbulent place, crossing to the lee side from the turnpoint. This was where he tumbled.

Flying with this zip open causes lots of strange inflations to the glider and makes it feel really unsafe (it certainly did when I flew my Xtralite 137 with the zip open by mistake).

(editor's note: Ron Richardson didn't mention any issues like this for his tuck. Still, it seems like there have been quite a few tucks and tumbles with rigid wings and over the last few months with ATOSes. There were various causes, but in Tryg's, Bo's and my cases, the glider broke while tucking. I'll have more on this later, with statements from Felix Ruehle, among others.)

Thu, Oct 25 2001, 2:00:02 pm EDT

Felix Ruehle|Ghostbuster|Pat Denevan

I had contacted Pat Denevan «mission» at Mission Soaring in Milpitas near the Ed Levin site on the southeast corner of the San Francisco Bay about getting a box to ship my ATOS back to Wallaby. Pat wrote back about his experience with shear ribs sewn into the ATOS sail.

I had tried shear ribs before on the Exxtacy and I had spoken with Kevin Cameron at the Lone Star Nationals about the shear ribs on his ATOS. I was skeptical about their actual effect on how the ATOS felt and performed. Pat had this to say about his experience:

I love the Atos except for the pitch disturbance in certain kinds of air. When the air is stable but choppy the glider bar pressure changes in disturbing manner. When I'm pulling in and get a bump the glider wants to dive and the bar pressure goes negative for a moment. At that point I feel like I really don't want to pull in more since it feels like it may want to continue.

Normally I just keep the bar in the same position and then I can ignore these bar pressure changes. When I demo the glider at Funston pilots find it disturbing enough to say " Feels Divergent". On the same day flex wing pilots might say it's a little turbulent. A good example of a glider that feels like this is the Ram Air.

One of the reasons this glider wasn't successful as it could be is the wandering pitch pressure. If we can get rid of this "divergent feeling " I could sell many more than the 14 Atos I have sold so far.

Steve Deleo, the new Ghostbuster dealer in the bay area, flew Kevin's Atos and then our demo. He said Kevin's was really solid feeling, the demo pitch was wandering, and his Ghostbuster was in between. I have never flown the Ghostbuster or Exxtacy. I flew a Fledge 1 in the late 70's. The pitch pressures were fine, I couldn't stand the tail heaviness and the set up was a real pain. The Fledge 2b tail heaviness was a back destroyer, so I went back to flex wings.

The Atos is the best rigid wing by a large margin and I have been flying both sizes, with a slight preference for the 146.

ATOS designer Felix Ruehle states that the shear ribs make no difference, and no one knows for sure as it is hard to quantify their effects. Pat mentions that it is possible to use sticky back Dacron tape to put Velcro strips into the sail to act as shear ribs. Perhaps I'll have a chance to try that out in Australia in January.

Obviously rigid wing hang gliders are going to have a different feel than flex wing hang gliders, but just what and why remain elusive. The ATOSes that I'm flown seem to have plenty of pitch stability, and I don't recall any "wandering pitch." Still I would like to find out more about this issue.

Aeronautic Innovation Rühle & Co GmbH|Felix Ruehle

Felix Ruehle «info» writes:

There had been an incident during the Italian championship with an Atos C prototype. The spoiler rope was winded around the spoiler lever. Though it was a prototype, this can happen with every certified Atos, too, during transport or set up. Through the friction at the lever, the spoiler rope rubbed off, with the consequence of loss of control.

Important before every flight: Check the control system by pulling at the spoiler cable. In the this case there was a strong wind at take off which made checking difficult. Additionally do a visual control cable check at the assembled glider. Best way to do this is to open the Velcro between the spoiler rib and the next rib in direction of the keel. The cable has to go straight from pulley to pulley.

In this case the pilot landed without injury with his rescue parachute.

More information at www.A-I-R.de. There will be a retrofit available at A-I-R or our Atos dealers, which tighten the spoiler cable during transport and set up.

Discuss "ATOS advisory" at the Oz Report forum   link»  

Wed, May 30 2001, 4:00:02 pm EDT

Felix Ruehle|USHGA|Valerio Canestrelli|Worlds

Valerio Canestrelli «vacanes» writes:

The Italian AERO CLUB will not sponsor the hang gliding team (both flexies and rigids) at the Worlds. As not every pilot can afford to pay the expenses, all the Italian pilots are protesting and have decided not to go to the Worlds, unless everyone can be supported!

We have, it would appear, one of the strongest rigid teams including the European Champion, Gaetano Matrella. Felix Ruehle was very disappointed to hear that we aren't going to the worlds! We are looking for some sponsorship.

(editor's note: I must admit that as an American I am not all that sympathetic. The USHGA does provide a small amount of support to US pilots going to the Worlds, but basically they are on their own. The idea of getting significant support from the national club or from the government is just beyond my worldview.

Isn't Spain just down the street from Italy? Weren't the last Worlds in Italy? Imagine having to pay for your airfare across the Atlantic to go to the Worlds, like we did and do.)

Tue, May 15 2001, 3:00:01 pm EDT

carbon fiber|Felix Ruehle|Florida|Mike Barber|Peter Radman|record|Steve Pearson|Wallaby Ranch

On Wednesday everything changed in Florida. For over a month we had had wind out of the east. After the Florida competitions The wind blew hard out of the east for two weeks and we didn't have any flying. Then a week ago Thursday, the winds finally calmed down and we were once again able to get into the air.

Still the air wasn't all that pleasant. Many pilots noted that it was "choppy" or "rolly." While the winds were light and there was moderate to good lift, its texture didn't feel quite right.

On Wednesday of this week the winds started finally coming out of the west and the texture of the air changed dramatically. For me the air now felt like the air that I had come to Florida for. No longer was I continually jarred about. It was smooth and a compete joy to fly in.

The Thursday two pm winds are forecasted to be out of the west, but the blue on the eastern half of the state shows that they will be less than 5 mph, due to the east coast on shore flow.

The area of convergence and light winds increases later in Thursday afternoon and moves further west over Wallaby Ranch.

The thermals weren't necessarily big and fat, in fact there were plenty of edges to them and you could get tossed around a bit. But no longer was there this continual hammering of your glider. Flying had once again become an enjoyable activity and not an ordeal to master.

Wednesday started out blue and there weren't any cu's forming until around 1:30 PM. The forecast called for west winds lightening up in the middle of the day near the Florida ridge due to the on-shore flow from the east coast. There was a strong lapse rate according to the FSL sounding for Kissimmee with a high cloud base at over 6,000'. That is where the cu's started popping.

Still the cu's took a long time to get going and it wasn't until 2:30 PM that we started launching. A very late day for Florida. The winds had been then lightened up significantly and we were getting a convergence zone over the middle of the state.

I flew with just an audio vario not even thinking about how good this day would turn out to be. Mike Barber, who had a student at his World Team Academy, would register 1700 fpm on his Tangent averager.

By 4 PM there were cumulus clouds every where and doing the 40 miles box to the north and west of the Ranch was as easy as pie. What was hard was getting down at the Ranch after the flight.

Soon after I figured out that I had just missed a world record day thanks to Mike. I hadn't thought about setting triangle records in Florida, but I just missed my big chance to really set a couple of new records and raise the bar way up high.

The forecast showed a similar day on Thursday, but with less lift predicted. Now that it was too late to take advantage of the best conditions, I was ready with my Colibri data logger and a two-task flight plan. Using the Seeyou flight planning and analysis software I was quickly able to create two FAI tasks for the right length just by right clicking on the task map and adding a couple of new turnpoints. I could then download the combined tasks into the Colibri to declare the task.

The FSL sounding prediction for Thursday 2 PM for Kissimmee shows a high cloud base, west winds and a moderate lapse rate.

Thursday started off with early morning fog that quickly burned off. It was nice to see that fog as it indicated light winds. Still, later in the morning there was a good breeze from the west.

Like Wednesday we waited and waited for the cu's to start forming. Not until around 1:30 did they begin to show up in the distance. It would be a while before they appeared over head.

It was not until 2:50 that I finally decided to launch as the clouds were now forming next to the Ranch. Twenty minutes later I was at 6,000', in nice warm air (no gloves), climbing at between 400 and 500 fpm. I headed straight for the start gate at Wallaby and took it at 3:16 PM at 5,700'. I knew that I didn't want to be too high, as I needed to get back to the Ranch at 4,100' or higher.

The Thursday 4 PM satellite image shows that there are small cumulus clouds over Florida, but not cu nimbs. 

I then headed northwest to the turnpoint only about 5 miles away at the headwaters of Withlacoochee River. I got lift right on the way that got me back to 6,000'. I didn't have to turn again until half way to the second turnpoint.

It took two thermals to get high coming into the second turnpoint at Dean Still Road and Old Grade Road (a former Wallaby Open start gate). I continued toward the Ranch after rounding the second turnpoint and got down to 3,100 two miles from goal. I only had to take the thermal that was there are marked by a cu to 4,900' to make it with enough altitude to get to the goal high enough to qualify the flight. The flight takes me all of 33 minutes.

I thought that I might try to gain a little altitude before I went off on my second task, but when I went back to get the lift it wasn't there. I decided just to head toward the first turnpoint using the finish point of my last task as the start point of this second task.

I had started a bit low 4594' and wasted a bit of time going in the wrong direction and now I was flying through light lift and getting down to 2,500'. I was trying to get under a good cloud and in some stronger lift. The cu's didn't have any vertical development to them, and the lift was only moderate.

By continually pushing out in front and not bothering with the lighter stuff, I was finally able to locate some 500-fpm lift that soon turned into 700 fpm. This would be the best lift of my flight and I would get the highest on this task in this thermal, 6,800'.

There were plenty of clouds on my way to the turnpoint at the intersection of 33 and 474, 9 miles to the northwest of the Ranch. I was able to climb back up to 6,400' just before the turnpoint.

Heading south to the next turnpoint southwest of the intersection of Dean Still and highway 33, I had to run a bit to the west to get under some clouds and I was down under 2,000'. I had to work 300 to 400 fpm to get back some of my lost altitude before I could slip over to the turnpoint to my southeast and get under a better cloud with lift over 600 fpm. I climb to 6,500' and it looks like I can glide back the 9 miles to the Ranch and make it will enough altitude to be within the 2% parameter.

I run back to the Ranch at 50 mph and get there with more than enough height having hit plenty of lift on the way. I complete the 50-kilometer FAI triangle task in under an hour and 15 minutes.

I go out again for a third time to see if I can break my new 25km-triangle record. At 5:30 I climb out 4 miles northwest of the Ranch to 7,500', the highest I've been in Florida this year, and race back to the Wallaby Ranch start gate to take it at 6,000'.

I find the next thermal half way to the second turn point, but the cu's are getting pretty sparse this late in the day, and although I climb back to 6,000' I'm not able to find enough lift to get me back to 4,500' as I go to goal.

The air was completely enjoyable and if setting records were always this much fun, there would be a lot more record setting going on.

Of course, I realize that these are very minor world records, and I probably wouldn't have even thought about breaking them, but I saw that Tomas was not too ashamed to do so this last summer in Wilcannia. I would have loved to have beaten Tomas's records, but it looks like I picked the wrong day. For these short flight, it appears to me that picking the day is the main pilot skill that is tested.

Of course, like during my world record distance flight, I used my wheels and my round Icaro base tube. I could have easily switched to my carbon fiber aerodynamic base tube with the micro skids, but didn't.

Thanks to Felix Ruehle for a fine ATOS glider. Thanks to Saskia, Gianni and Peter Radman for getting it to me. Thanks to Nene Rotor and Carlos Bessa for getting me a a slick Rotor harness (is a bit too big around for me though). Thanks to Steve Pearson for the WW Slipsteam down tubes, George Ferris for the Tyvek glider covers, and Heiner Beisel for the Heads Up.

Mon, Mar 26 2001, 3:00:03 pm EST

Felix Ruehle|Gary Osoba|Richard Nikoley|weather

Richard Nikoley «rnikoley» writes into the rigid wing list with this discussion of pitch changes while flying his ATOS:

Ever since taking delivery of my Atos nearly a year ago, there's been one aspect that I've always found uncomfortable, and that's what I'll call an "active bar." By this, I mean that no matter what speed at which you're flying, there can often be continuous and automatic pitch changes, the severity of them proportional to the amount and strength of turbulence in the air. As someone who came from an intermediate flex wing, I was dialed into feeling steady bar pressure with increased speed, and at a point, there's virtually nothing short of severe turbulence that will alter the strong pressure of the bar.

Not so with the Atos. Even thermalling at 35mph on a high-pressure day, I can have the bar instantly dive from my chin level to my chest level, causing very uncomfortable feelings.

Recently, Davis broached this subject in the Oz Report in reference to George Farris' Atos. But, after a thorough check of my nose angle, I'm right on the money. Moreover, I recently switched from the turnbuckle to the lever, made no changes to the way the lever came setup, and the glider flies the same. I find that even in coastal ridge lift at Funston, I sometimes experience the bar active in pitch, although small and not disconcerting.

Yesterday, I had the opportunity to discuss this with Steve Morris while at Funston and he really went a long way to setting my mind at ease. According to Steve, rigid wings with inherently pitch stable airfoils do this naturally. It is simply the wing reacting to changes in angle-of-attack induced by lift and sink. Apparently, the wing will tend to initially dive into lift, and mush into sink. Flex wings tend to stall and recover, leading to a different "feel" altogether. This seems to match what I have experienced. He also mentioned that Mill pilots have made the same "complaint."

Stephen J Morris «mlbco» responds:

I mentioned to Rich Nickoley that most rigid wings I know of are more 'pitch active' in turbulence because of their pitch stability. Rigid wings have a fairly linear pitch moment versus angle of attack in the range before stall. Flex wings, on the other hand, can have a very little variation of pitch moment because of wing flexibility (at least until the dive recovery system kicks in). Gliders that are more pitch stable will 'follow the air' more closely in gust conditions.

Imagine moving a weather vane through a thermal at 30-mph speed. When you hit the edge of the thermal the vane will point downward (into the gust) and likewise will point upward leaving the lift. These are transient effects but are very noticeable to us pilots. Rigid wings behave more like the weather vane than flex wings. It may feel uncomfortable but it is perfectly normal and possibly safer because the wing that pitches is less likely to have a gust induced stall. Of course flex wings have their own tricks for avoiding stalls such as gust-load induced twist, but that's another story.

The idea of a wing pitching down and accelerating into an up-gust is equivalent to what happens on a bird's wing on the down stroke of the flapping cycle. The wing angles downward but holds (or increases) lift and there is a forward thrust on the aircraft. The opposite happens when hitting sink. Gary Osoba has been investigating taking advantage of this effect for more efficient soaring. For low wing loading aircraft it is mostly a nuisance and limits our maximum comfortable speed in big turbulence. Flex wings aren't as bad in this respect because their wing flexing dumps some of the gust load.

Felix Ruehle «felix» writes:

In the factory we started adjusting the ATOS in autumn 2000 with higher twist giving the glider a higher bar pressure and also with a little more sweep. After the first flights especially in wet air the sail would get loose. When the sail is loose the sweep is less (as the leading edges aren't pulled back as much).

It is necessary to check the sweep and maybe to tighten the webbing connection from the sail to the keel. With less sweep theoscillation is much stronger. To be on the safe side, the sweep must be more not less. This was the reason why we are adjusting the gliders from autumn 2000 with more sweep (mark at the keel for measuring is about 1 inch further back).

(editor's note: Again, the ATOS that I just received was marked 2295 mm (90.35"). I measured this mark to be 2285 mm (89.96") with a measuring tape pulled tight. The glider was set to this mark.)

Wed, Jan 24 2001, 11:00:04 pm EST

carbon fiber|Davis Straub|Felix Ruehle|Florida|Hansjoerg Truttmann|Manfred Ruhmer|Rohan Taylor|USHGA

Last year in Australia I flew the same ATOS that I am flying this year. I flew it with a round base tube, standard down tubes, standard wires, bar mitts, and my carbon fiber harness. I had an identical glide ratio to Gerolf as reported last year.

This year I am flying the same ATOS with a new sail, a new nose lever, new nose cone, and new tip wands with cams. I am using my aero base tube, Sensor downtubes, no bar mitts, standard wires (I used thin ones in Florida and Texas), and my carbon fiber harness.

Gerolf has a new Moyes Litespeed with what looks to be a copy (improvement?) of Wills Wing carbon fiber control frame. He has made special tuning adjustments (and perhaps other adjustments) to his Litespeed (or so he says) including thin wires. He is very clean in his M2 Cigar harness (only one of three ever made).

I had a chance to fly within fifty feet of Gerolf for over 5 kilometers. I could not detect the slightest difference between us in glide ratio at speeds over 40 mph (the speeds we were flying at).

On the second to last day at Forbes, I did start out about 200 feet above and a bit behind Gerolf on final glide from 22 kilometers out. I took a more direct line to goal. I was willing to pull in at the beginning of the final glide and go faster than Gerolf and Betinho who was in front because I believed that I could out glide them. I felt that they would hold back a little bit in the earlier parts of the glide because they would be a bit less sure as to whether they would make it to goal, and I could use this to my advantage to get ahead of them. I was able to beat Gerolf by a minute.

Gerolf has a slightly better climb rate than I. We are usually thermaling at higher speeds in turbulent air.

Gerolf has noticeably the best climb rate (Rohan is very close, maybe the same) and the best glide ratio of any of the flex wing glider/pilots here. His superior glide and sink give him the opportunity to use his superior piloting skills (patience, strategy, experience, and desire).

Berndt tells me that he consistently out glides Gerolf in his ATOS at home in Germany. In addition, Hansjoerg has told me the same thing re Manfred. Berndt says that Felix Ruehle also out glides Gerolf. Berndt mentions that Felix carries a lot fo weight naturally and with ballast. Berndt was carrying 8 liters of water in his harness.

Berndt was not out gliding Gerolf here in Australia. Berndt was having a few tuning problems with Christof's ATOS. The bar pressure was higher than Berndt was use to. Berndt broke some ribs and didn't get them rebuilt correctly.

Berndt's harness is not as clean as Gerolf's, but he claims that he can still out glide him on his ATOS at home. I wonder what is going on here. Ballast? Differing ATOSes?

The ATOS performance here in Australia is only equal to the very best flex wing (and very clean harness and instrument pod), which is quite a bit better than the next best flex wings. I feel that it should be better than the best flex wing, but I will have to see when I get back to the US.

When I flew my ATOS in Texas at the Lone Start Championship last August, I felt, and the results showed, that it was much better than any flex wing glider at that meet. Unfortunately, the best flex wing pilots in the world were not there.

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Davis Straub
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