I agree that they do help slow up. They do alter the attitude which would indicate that there is something happening to the lift/drag ratio but I am not sure I would bet my privet hedge on the effect on stall speed :( I have wimped out of actually doing a full flap stall test.
In my experience landing distance is effected much more by weight. I can land happily in 400 yd on low tank, but with a full tank I just cannot get a good approach angle (even with full flap) and need up to 700 yds. Of course this is a cg issue but any increase in weight needs more lift leading to increased angle of attach for a given speed which takes us close to the situation where the aot to take off is very close to the stall aot. This all does my head in, so I would go with the old kiss mantra - light and simple. Pete -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. phil brookman <pjb1234...@yahoo.co.uk> wrote: in my experience the kr flaps realy do something ===no doubt about it about 3 knots .. i am just looking at v g s ..possibly increasing wingspan a bit ==look at diehl wingskins phill _____________________________________________ From: Peter Diffey <pe...@heroic.co.uk> To: KRnet <kr...@mylist.net> Sent: Wed, August 3, 2011 10:16:56 PM Subject: Re: KR> Flap and belly board combination. Hi, I am no expert, but as far as I can figure, a belly board will increase drag but will not increase lift, so will not allow a lower landing speed. The belly board drag will allow a steaper approach, it will also help you bleed off speed during the roll out. Whether the kr2 flaps have any significant effect on stall speed is a moot point, I doubt if anybody has done any design analysis. Looking at the flaps on my std kr2 I doubt if they do much to stall speed. The easiest way to keep down the safe landing speed is to build light - I thought hemlock was a sort of poison :) Pete -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. Rodger Nicolls <bandenok...@gmail.com> wrote: Phil and Larry, Thank you for the replies. I am looking at dropping the stall/landing speed, increasing the visibility, and contending with a heavier empty weight (using hemlock, 10% heavier than spruce, with extended fuselage). I have moved the controls in front of the rear spar and plan to use the entire area behind the spar for the flaps. On anther note: I completed building my gear legs: 50 layers S-glass-BID and 38 layers S-glass-UNI, with a total compressed/cured thickness of .80". Now I just need to get the mount welded. If anyone is interested in the story (with pictures) of an experimental Cub being destroyed by a calving glacier, let me know and I'll forward those to you. It's a shame that after spending all that time on a lovely project to see it lost in a matter of seconds. I will continue to build. Thanks, Rodger _____________________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html _____________________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html _____________________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
