At 12:34 AM 3/10/06, D F Lively wrote: >I am taking over a KR2 project ... >I intend to do all that I can to get it under sport-plane limits ...
Keep in mind that LSA requires the 52 mph max stall speed clean, and at gross weight. This means that you can _have_ flaps, but you cannot use them to arrive at your stall speed limitation. For stall speed calculations, you need weight (gross in the case of Light Sport), wing area, and coefficient of lift. For anyone playing with this idea, there is some good information here: http://zenithair.com/kit-data/ht-86-8.html Down near the bottom of the page are formula for estimating speed and stall. You need CLmax for the stall estimate; according to http://www.krnet.org/as504x/design.html the CLmax for the AS5045/8 wings is 1.28 clean. <Mark L, am I reading this wrong?> According to http://fly.hiwaay.net/~langford/kraf48.html the RAF48 has a CLMax of 1.42 without flaps at 18 degree AOA, so for this purpose it might be more suitable. Playing with this info, it looks like a 700 pound gross, with 78 sf wing area, and the RAF48, would give you a stall of 50 mph. Another way to look at it, with the RAF48, you can have a maximum wing loading of 9.468 lb/sf. With the AS5045/8, you need a max of 8.873 lb/sf. Top speed is a lot easier to do during the test phase; just decrease the maximum continuous rpm limitation to give you the desired top speed (138 mph). Bear in mind that all the above is just desktop theorizing based on the published limitations of the Sport Pilot rule. Or, as the British say, wanking ;-) Regards, RonB
