The question has been asked "what do the holes do for you". If I hadn't just asked an aero engineer that I have a LOT of respect for, I'd have said "they increase drag due to the turbulence created in their wake". But he assures me they DON'T. So why do they have holes then? He says it's to alleviate any aerodynamic fluctuations (vibration) and to reduce the lift. Say's it probably started with the Avenger, because the drag brake configuration yielded more lift than they wanted, so they put holes in them to eliminate the lift. That same logic probably applies to the KR. Lift while in ground effect is not something you need any more of.
As for what's the difference in a flap and a drag brake, a flap is designed to give more lift so you can land slower, while a drag brake is designed to give you a lot of drag to slow you down and steepen your glide path. A "split" flap gives you some of both. Sounds like some testing is in order. One of you belly flap guys could temporarily cover up the holes and see what difference it makes, if you reallly want to know... Mark Langford, Huntsville, AL N56ML at hiwaay.net see KR2S project N56ML at http://home.hiwaay.net/~langford
