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RE: Europa-List: Wing incidence

Subject: RE: Europa-List: Wing incidence
From: Christoph Both <christoph.both@acadiau.ca>
Date: Sat, 2 Aug 2008 11:09:20

Hi,

There have been comments regarding binding wing pin bushes:


Much of this is caused by a serious flaw in the Europa Builder's Manual: 
when initially setting the wing spars (or XS wings) to the cockpit 
module the manual allows you to let them assume any position they like. 
In other words, the wings might hang around at 5 or more degrees wing 
incidence. This uncontrolled condition causes the wing mounting pin to 
increasingly deviate from the wing bush bore incidence in the back of 
the cockpit module. So, if you just glue in the seat back bush without 
taking care of approximating as closely as possible the 2.5 degree later 
wing incidence the following will happen for sure:


Upon finally setting the wing incidence the pins will now be a few 
degrees off level with the drilled hole level of the seat back bush, 
thus binding like crazy.


Initially I could not believe how stupid I was using a REAMER to ream 
through the two wing mount bushes plus the seat back bush. YEAH, I could 
now easily remove the wing pins but the entire set up was now 
compromised beyond any airworthiness considerations. All this was caused 
because no hint was given to incorporate as closely as possible and 
already at the early building stages, the 2.5 degree wing incidence so 
the seat back bush would not bind. 


I fully came to terms with this much later while upgrading to 1/2 
diameter bushes. While replacing all bushes in the wings I made sure the 
seat back bush had the right angle. This almost solved the problem. 
However, I did have some persistent serious binding on one side. In the 
end I had to reposition one of the new wing bushes in situ, that is, 
floxing it in while the wings were mounted. Don't ask me how I managed 
this with the wing fillets already on and both wings mounted. I had to 
create a special sequence of steps and some innovative tools to get this 
resolved...


The wings are now fully up to mounting standards and go effortlessly in 
and out of the fuselage with the wing mount pins sliding in and out 
smoothly. What a joy!. Oh, by the way, you need to make a well 
positioned wing mounting bracket (see picts) to achieve this as well. I 
can now mount my classic wings alone, without extra tools and special 
assemblies. I used pieces cut from  1/4 inch UHMW plastic sheet which is 
incredibly tough but somehow flexible and slippery when the wing spars 
glide on it, without any chance of scratching or abrasion. Incredible 
stuff and much better than the phenolic sheets! 


I hope EUROPA updates the builder's manual to save us many frustrating 
hours. It's a great kit, though, I must say.


Christoph Both

#223
Wolfville, Nova Scotia, Canada 



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