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Larry, I waited a while to respond to see what other answers were given (and because I was fairly busy when I first saw your question). As designed, the Coupe's wing is designed to stall from the wing root outward in a fan-shape (hugging the fuselage at the wing-front and fanning out at the trailing edge). As you get slower yet, there will bee some stalling of the wing root. area. This burbling of the air-flow will cause turbulence at the tail, reducing the tail's lift (downward vector pushing the tail down). The downward pressure on the tail is limited by elevator up-travel limitations AND will be further limited by this burbling/turbulent airflow over the tail. Here are my observations, based on a 415-D. Within certificated gross weight and CG, a no-power stall is a non-event. It bobbles a bit and keeps on gliding straight ahead. AT gross weight and near rearward CG, the more power I added, the more the slipstream pushed down the tail and the slower became the stall speed. Similarly, the more power, the less polite became the "stall" behavior. As I neared full power, I got results similar to yours. The stall break got more pronounced (though it was NEVER a fully developed stall - like most well-designed planes, I was able to maintain aileron control throughout the procedure). The worst case condition I tried was about 100 rpm below full power, full up elevator (9?) and FULLY CROSSED CONTROLLS - left-full-rudder and enough right aileron to keep it going straight! In this condition, I got a distinct break, loss of climb and it circled slowly to the left. AS SOON AS I relaxed the controls a bit OR reduced power, I was back in full control (no left turn). I'd bet that a Coupe at 1260 lb. would also do as well with fully crossed controls. I seem to recall Fred Weick telling me at an Iowa regional fly-in that the Coupe was certificated as spinproof WITH and WITHOUT rudder pedals. I would not want to predict behavior with 13? of up-travel, 1400 lb. gross weight and fully crossed controls except that I want to wear a parachute when flight-testing it. (Some unusual altitude aerobatics can get you nose-down and picking up speed very fast.) Doing this same test in a Coupe with rudder interlink and no pedals, I'll go for the ride and won't worry about the parachute. I'd ask you to get out your weight and balance paperwork and do a full weight and balance calculation for the flight you had the unpleasant full-power stall test. Please let us know the model, elevator up travel, gross weight and CG. Considering that you were testing at full power (maximum down-push of the tail from the slipstream), I'd say your resulting flight behavior was not out of line. Ed Burkhead http://edburkhead.com/ ed -at- edburkheadQQQ.com (change -at- and remove the QQQ) I know you believe you understand what you think I said, but I am not sure if you realize that what you heard is not what I meant. (Jim, AKA Midnight Plowboy) -----Original Message----- From: Larry Snyder [mailto:[EMAIL PROTECTED] Sent: Sunday, February 27, 2005 6:50 AM To: [email protected] Subject: [COUPERS-TECH] Unusual stall behavior ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- All, I have read in many places that an Ercoupe doesn't stall, it just loses altitude. I was out with my instructor yesterday and my 415-C had some odd behavior at slow speeds. Under full power, at about 60 mph indicated (or a bit under) the left wing would just drop, along with the nose. It would quickly recover, since as soon as the nose dropped it would pick up speed. I had to give it right aileron to try to level the wings. At idle, the behavior was kind of scary - at 50 or 55 the left wing would drop again, sharply, along with the nose. I was pretty quickly looking at the ground! I could push the nose down and quickly recover in about 50 feet, and if I gave it full throttle I could recover with almost no altitude loss. I know now how to handle these situations, but they don't seem like typical Ercoupe behavior. Could the rudders not be adjusted correctly, causing the plane to be uncoordinated? I always received a warning before the stall - my left wing would start to drop off. Thanks for any information on why it might behave this way. Larry N99430 ======================================================================== ====== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/ ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/
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