http://ozreport.com/12.037#0

Gerolf Heinrichs <<email>> writes:

I’m pretty sure you’re not gonna print this one again, however, I think it’s quite interesting.

As you know, at the annual Anger winter glide comparison event they have hang gliders of different classes perform a task that is basically to take off from one side of the valley, cross it and land above a certain line (goal line) on the slope on the other side – your score is the time you need from take off on one side to passing the goal line on the other. The altitude difference is 300m, the glide distance 3km, so the task really is to perform a 10:1 glide as fast as you can. Since, there are no more rules (e.g. wing loading unfortunately is not regulated, and wing span is never considered an issue), you often see a lot of guys trying to pull off the impossible and smash hard into the other side of the hill :-(

On the A.I.R website (www.a-i-r.de) we find a graph comparing the average speeds of different classes over the past years. Of course – surprise - they make it not look too good for the Flexis :-)

This season we find the Atos VR winning 93kmh, while Seppi on his small Aeros got it (e.g Tom Weissenberger did 81kmh on his RS-4 last year). The difference may look quite significant, however, you need to see the span advantage the Atos-VR has over the flexies: about 33-40%. And the wing loadings in this event usually compare like 11kg/m² against 9kg/m², a 20% difference.

Right now, as we speak the competition in Bassano, Italy is going on. On the first day the Flexwings and the Rigids flew the same task (110km), there may have been a difference in start radius of 2km, but: The flexies won this comparison by miles.

Michi on his Moyes Litespeed RS-3.5 finished in 1:55 (four minutes ahead of the next flex wing). Walter Geppert on his Atos VR in 2:07 (eight minutes ahead of the next rigid wing). What do we conclude now?

That the Flexies can use their nominal performance more efficiently then Rigids? That they get back some, if not all, their glide handicap 10:1, from better climb and better maneuverability near the ridge? Or simply that machine performance is overrated and it all still comes down to which machine is steered by the better pilot?

If so, we then would still always have to answer the pressing question: Why do top hang glider pilots still prefer to hang under a flexible wing, when given the chance? ;-)

First, I always love it when Gerolf argues that the flex wings are better than the rigid wings. As I won the Australian National Championships twice flying an ATOS, beating Gerolf and all the other flex wings (as well as the few other rigid wings), I like to think that Gerolf knows that I'm the better pilot and that's why I won. :-)

Second, I don't know if the question, which glider type is better, is site and conditions specific, but it may be.

Third, top hang glider pilots may prefer the higher level of competition among the flex wings that comes with most competitions where few rigid wings are flying. I know that that very much influences me.

Fourth, I prefer to hang under a flex wing because I haven't had one tuck and tumble on me. But that was before the tail. Still it is my personal history. Maybe other pilots prefer the "feel" of the flex wing glider to that of the rigid wing.

Fifth, vast prices differences may affect this decision (see a follow up article coming soon).

Sixth, most top pilots actually prefer to fly paragliders, so maybe performance is not the primary issue.

I think that Gerolf raises some interesting questions, but muddies the water a bit (as do I) with his final question. Perhaps Oz Report readers have some real answers for him to his serious questions.

I would say that on average the VR climbs better than any flex wing, but there may be circumstances where the flex wing has an advantage. I don't think that on average the flex wings have an overall performance advantage, quite the contrary.

I believe the results of this one day in one contest indicate that Michi was the better pilot. Pilot skills are widely divergent. They can easily overwhelm differences in glider performance. That's why manufacturers want the best pilots flying their gliders.

There was only one valid day at Bassano apparently. The results can be found here: http://www.aeroclubmontegrappa.it/flex-task-1.html and here: http://www.aeroclubmontegrappa.it/rigid-task-1.html. There were eighty seven flex wing pilots and only twelve rigid wing pilots. Thanks to Vicki Cain.