As usual, Syd hit the question right on the head with the right facts. As an aside, Fred Weick told us once that he never thought the aileron weights were needed. The CAA was going through a binge of wanting the weights on lots of planes, he said.
Do pay attention to the freeplay listed in Syd's quote of Ercoupe Service Memorandum No. 57, below. On the day I learned about this stuff, I was doing a high speed descent in PERFECTLY smooth air and gently let the speed approach 144 mph, Vne. Somewhere near 135-140, I hit a washboard road. The instant I saw the fluttering ailerons, I loaded the surface with a turn which stopped the flutter before the aileron departed the plane. Consensus is that I was lucky I had that much time (2-3 seconds) to perceive and do something about it. My aileron free play was NOT within the 5/16 of an inch. This is a check I have never thought of again as optional. [EMAIL PROTECTED] wrote: > > Cecil Myers wrote: > > > Help! anyone; > > > > I have found in ercoupe aileron parts list that a balancing unit is > > listed. I have owned Ercoupe N87435 for ten years and it has'nt had > > units on it all this time, it's been annualed each year and no mech. has > > mentioned them being gone. What's the deal are they important or not? > > If they are important what is the procedure for ballancing them? > > > > Any suggestions? > > > > Cecil, > Ercoupe Service Memorandum No. 57, dated October 11, 1949, titled > "Aileron Balance Weight Removal," says: > > "In the past, some difficulty has been experienced with the attachments > of the aileron balance weights. These balance weights, in addition to > being a maintenance problem, might present a flight hazard if permitted to > become loose and remain that way. > > "As a result of recent test and analysis, it has been determined that > the aileron weights on the Ercoupes may be removed and the aileron will > still maintain freedom from flutter throughout the operational range of the > airplane, provided the aileron free play does not exceed 5/16". > > "In order to measure aileron free play, one aileron should be blocked > in the neutral position and the free play measured at the trailing edge of > the other aileron. In checking the motion, care should be taken not to > exert sufficient force to deflect some of the members, thereby getting a > false reading. (See Service Memorandum No. 56) > > "It is recommended the aileron system be checked for free play after > every 100 hours of operation and if measurement exceeds 5/16", all joints > and bearings should be checked and those which are loose should be > tightened or replaced. > > "Removal of aileron balance weights is not mandatory, but is > recommended for all Ercoupes Model 415C, 415CD, 415D, E, and G. The weight > of the parts removed totals 3.5 pounds and their CG is 55.5" behind the > datum line." > > Cecil, you can get a book containing all of the Ercoupe Memoranda and > Service Bulletins from Univair or Skyport. I highly recommend every > Ercoupe own one. > > Syd Cohen > Wausau, WI > NC94196 > > --------------------------------- > to unsubscribe send mailto:[EMAIL PROTECTED] > _____________________________________________________________ > Want to find the best email lists? Check out the Topica 20! > http://www.topica.com/topica20 -- Ed Burkhead Peoria, Ill. Ercoupe N3802H, 415-D --------------------------------- to unsubscribe send mailto:[EMAIL PROTECTED] _____________________________________________________________ Want to find the best email lists? Check out the Topica 20! http://www.topica.com/topica20
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