Bob McArdle wrote: > Its time to replace the donuts on my '65 Alon. I thought about Bellville > springs but the cost does'nt seem to justify the change. Right now the > tail sits at 72" instead of 75". My question is: Will my take-off roll > on grass be more or less at 75" than at 72" and why?
Bob, The tail at 72" instead of 75" isn't a crisis. If you haven't replaced the donuts recently, I'd suggest doing it at the next annual or when you have a convenient opportunity. I've heard people talking about their old, drooping Bellville springs. I don't know if it's worth the cost to change to them. Donuts are pretty cheap and even I, the mechanical klutz, managed to change my own donuts during an annual a few years ago. Your take off roll on grass or pavement may be slightly longer with the tail at 75" as opposed to 72". This is just because you'll need a bit more rotation which means a touch more airspeed over the tail to push the tail down for that rotation. A tail dragger drags its tail partly because that is the correct attitude for short field take-offs! Having said that, I doubt you'll be able to measure or see the difference between having the tail at 75" or 72". You may see a difference between the two in strong cross winds. With the tail drooping and the wings at a bit higher of an angle of attack, you may get more lift of the up-wind wing. Again, for a tail difference of 3 inches, I'm not sure you can see or measure the effect. Between 69" and 75" I'm sure you'd think the improvement is important. I can't quantify any of these statements. They are based on talking to a lot of Coupers so please assume this is very fuzzy information. Ed __________________________________________________________________________ ______ To unsubscribe from this list please send mailto:[EMAIL PROTECTED] ___________________________________________________________ T O P I C A The Email You Want. http://www.topica.com/t/16 Newsletters, Tips and Discussions on Your Favorite Topics
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