Date: Fri, 31 Jul 1998 12:29:49 -0700 (PDT) From: Mark Loy Subject: COZY: Deep stalls Hi to all. As one who is going to build a Cozy MkIV (as soon as I order the plans), I would like some input and discussion on the stall characteristics (or lack thereof) of this airplane. I've read about the tests that Nat did with the adjustable weight and the modifications done to the canard to stay away from the main wing stalling. What I am concerned about is that per chance (and there ALWAYS is a chance, even with correct build as per plans and correct c.g.(or is there?)) that a situation arises that the pilot gets the main wing to stall, is he or she toast? I've done my fair share of stalls, spins and spin entries in Cessnas and Cherokees, and there is always a recovery (assuming there is enough altitude). Am I ignorant in thinking that a deep stall is NOT IMPOSSIBLE when the plane is built correctly and flown within proper c.g. or am I just a worry wort? Enlighten me. Thanks, Mark W. Loy _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com Date: Fri, 31 Jul 1998 16:14:33 -0400 From: bil kleb Subject: Re: COZY: Deep stalls Mark Loy wrote: > > I would like some input and discussion on the stall > characteristics (or lack thereof) of this airplane. for immediate gratification, you might what to avail yourself of the group's archived discussions on deep stall at http://cozy.canard.com/mail_list/topics97/deep_stall.txt http://cozy.canard.com/mail_list/topics96/deep_stall.txt or mailto:majordomo@canard.com with the following as the message, get cozy_builders topics97/deep_stall.txt get cozy_builders topics96/deep_stall.txt end if you're web-disadvantaged... -- bil From: cdenk@ix.netcom.com Date: Sat, 1 Aug 1998 14:48:25 -0500 (CDT) Subject: Re: COZY: Deep stalls GBerven writed Subject: Re: COZY: Deep stalls >stalling. What I am concerned about is that per chance (and there >ALWAYS is a chance, even with correct build as per plans and correct >c.g.(or is there?)) Point the airplane straight up, and run out of energy, the airplane will stall, wings, rudders, fuselage, wheels whatever. > that a situation arises that the pilot gets the >main wing to stall, is he or she toast? Short answer is NOPE. If the airplane built according to plans and is flown within the CG range, recovery is possible. > Am I ignorant >in thinking that a deep stall is NOT IMPOSSIBLE when the plane is >built correctly and flown within proper c.g. or am I just a worry >wort? Enlighten me. The canard design will help prevent the main wing from stalling. There was a worry about getting locked into a deep stall, where airspeed approached 0 and the controls were ineffective. The vertical speed was such that the airplane was flying at a high AOA (relative wind), and the engine didn't have enought horsepower to overcome the drag. Keeping forward speed above a certain point will probably prevent an unrecoverable situation (assuming enough altitude). Keeping CG in acceptable range or forward of acceptable range will help insure this. From: "Nat Puffer" Subject: Re: COZY: Deep stalls Date: Mon, 10 Aug 1998 11:12:15 -0500 Dear Mark, When we added lower winglets (per plans) and shortened the canard span 6 inches from what was shown in the 1st edition plans (the 2nd edition was updated) our plans-built Cozy Mark IV would not stall in level flight even 1.3 inches aft of the recommended aft c.g. limit. Before we added the lower winglets and shortened the canard span, we were able to stall the main wing. We did this about 12 times, and recovered without having to move the weight and move the c.g. forward. But we applied forward stick before losing forward speed. We had one instance of a main wing stall by Pat Young. However, his airplane was not built according to plans, his canard was not mounted at the correct angle of incidence, he had made a mistake in calculating his c.g. He knew his airplane was not flying right during the first 14 hours before he stalled it (he had previously built a 3-place, so he knew how the 4-place was supposted to fly), and he attempted an accelerated stall, and didn't recover soon enough. We regret that he never contacted us during the first 14 hours, because we could have advised him that something was wrong and he should ground the airplane until he found out what it was, and we could have helped him do that. We guess he was relying on less than a knowledgeable source for advice. We don't know why he didn't check with the designer. Regards, Nat ---------- > From: Mark Loy > To: cozy_builders@canard.com > Subject: COZY: Deep stalls > Date: Friday, July 31, 1998 2:29 PM > > Hi to all. As one who is going to build a Cozy MkIV (as soon as > I order the plans), I would like some input and discussion on the > stall characteristics (or lack thereof) of this airplane. I've read > about the tests that Nat did with the adjustable weight and the > modifications done to the canard to stay away from the main wing > stalling. What I am concerned about is that per chance (and there > ALWAYS is a chance, even with correct build as per plans and correct > c.g.(or is there?)) that a situation arises that the pilot gets the > main wing to stall, is he or she toast? I've done my fair share of > stalls, spins and spin entries in Cessnas and Cherokees, and there is > always a recovery (assuming there is enough altitude). Am I ignorant > in thinking that a deep stall is NOT IMPOSSIBLE when the plane is > built correctly and flown within proper c.g. or am I just a worry > wort? Enlighten me. > > Thanks, > > Mark W. Loy > > > > > _________________________________________________________ > DO YOU YAHOO!? > Get your free @yahoo.com address at http://mail.yahoo.com >