Decalage Angle

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Skyboy68
Posts: 1
Joined: Thu Mar 09, 2017 10:41 pm

Decalage Angle

Post by Skyboy68 »

Hi all, new member here. Six months ago purchased Skyboy EX with 100 HP Rotax. High wing pusher fabric wing and tail.

Very short version for very long issue -

My instructor didn't like flying characteristics of this airplane at first. Airplane is flying straight in level with a very high angle attack. I am flying by myself now, and I think I am getting used to it, but still don't like it. After doing a lot of homework I and up discovering that my decalage angle is 9 1/2°. another words, when airplane is sitting on the perfectly level ground, which is supposed to be straight and level flying attitude, the wing is pitched up by 4 1/2°, but tail pitched down buy 5° negative. Gives me a total of almost 10° differential between two surfaces. I am Cessna trained pilot. It feels to me like I am flying around with fully extended flaps.
Does anybody have a knowledge in this area?
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MrMorden
Posts: 2184
Joined: Fri Aug 17, 2012 7:28 am
Location: Athens, GA

Re: Decalage Angle

Post by MrMorden »

A friend of mine had a 912-powered Skyboy for a long time, he just sold it. It always seemed an odd airplane. It looks slippery and like it should be pretty fast, but it's not. It also didn't have great glide and seemed to need to land faster than you'd think. It was a neat airplane, but with some interesting limitations.

As for the strange deck angle, I wonder how much of that might be necessitated by the pusher configuration and the high thrust line? Just guessing since I have no time in pushers, but do know they are known for odd and sometimes "backward" characteristics compared to tractors.
Andy Walker
Athens, GA
Sport Pilot ASEL, LSRI
2007 Flight Design CTSW E-LSA
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FastEddieB
Posts: 2880
Joined: Wed Jan 07, 2009 9:33 pm
Location: Lenoir City, TN/Mineral Bluff, GA

Re: Decalage Angle

Post by FastEddieB »

Andy,

We did go up in the Sky Arrow once, right?

I was surprised how little difference there is in flying characteristics.

"P factor" would call for left rudder in the climb, but with the thrust line so close to the CG it's virtually unnoticeable in my plane.

And nothing unusual about the fuselage angle in flight, either.

So I don't think it's a pusher thing.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME
[email protected]
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