Saturday, January 5, 2013

Adapting the Combat to the heat

The first few days in Australia, I was surprised how tough hang gliding was. The glider was really hard to steer and I originally thought that was caused by the turbulent air and the lack of flying in the past 3 months.

It took me a while to realize the heat was causing it. Our sails shrink with increasing temperatures, so you have to decrease the batten length (it took about 3 turns on my inner battens and 1 or 2 on the outer to cover the 20 degree difference between last setup in Belgium and here). As important is what happens along the wing span. The Combat has rings (shims) which can be used to extend the leading edge. Mine was delivered with 4,5 mm rings. That's quite a lot, but when my glider was test-flown in January, temperatures were -30 in the Ukraine. That's 70 degrees difference to the 40 degrees we've got here. The result is that my glider became very slow in roll control because of the high lateral tension in the hot temperatures we experience here.

I made a drastic change and removed the 4,5 mm rings. The glider now has a surprisingly light handling, but bar pressure on fast glider has also increased significantly. Too much of a change. Luckily Paris went from 3 to 2 mm on his Combat and I'll be able to use his 3 mm rings on mine. I think that will provide a nice compromise.

So, anybody who's having a different glider between summer and winter: think about adding/removing rings to the leading edge. It does make a difference.


  1. Wow!
    But I am not 100% sure what you mean with the rings?
    Maybe you find the Time to add a PIC?

    greets from Austria and go4it!

  2. Hey Matze! Those are the rings at the outer end of the leading edge. They extend the leading edge with a few mm as desired. You find them between the actual leading edge and the black cap, which holds the sail.

  3. Aaaaa, Yes. Thank you.
    I can remember. It is also used when the glider is not flying straight?! To adjust the direction...

    Thanks, and go on!

  4. No, you can use the rings to change overall sail tension. I don't think it is effective as a non-symmetrical correction. If you have a turn without VG, adjust the tip angle (by rotating the leading edge cap). If you have a turn with lots of VG, use the sprogs to correct for that.

    1. The rings change the overall sail tension and thus influence how much tunnel the glider has. Less tension = more responsive handling, but more pitch.