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  #1  
Unread 12-20-16, 02:39 PM
B2C2 B2C2 is offline
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Level flight requires slight right hand turn input

Since I purchased my 1969 T337D about 4 years ago, I have had a need to put in a slight amount of right aileron deflection for straight line flight. The amount of aileron deflection needed is about 1/4-3/8 inch as measured by looking at where the aileron is w/respect to the wing tip, or about 5-10 degrees of right turn in the yoke. I have played around with using rudder trim and also the aileron trim tabs to compensate for this but there isn't enough adjustment there to center the yoke in flight. With the right turn in there from the ailerons and no rudder trim deflection the ball is pretty well centered and the plane makes book numbers for speed. It has a Robertson kit installed as well. I was wondering if anyone else has seen this behavior and if so is there a way to address it? It's not a critical problem but kind of bothers me that the yoke isn't centered and the ailerons faired with the wing tips and flaps in level flight.
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  #2  
Unread 12-20-16, 09:16 PM
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hharney hharney is offline
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Does the airplane fly straight and level? Your concern sounds like the yoke is not centered?
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  #3  
Unread 12-21-16, 03:04 AM
B2C2 B2C2 is offline
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Hi herb

Yes once the yoke is turned slightly to the right it flies straight and level with the ball pretty much centered. I spoke to my mechanic about it and he said it is acting left wing heavy, which doesn't mean it's necessarily heavy on the left side, but probably has a slight difference in the apparent Angie of attack of the two wings. Given the amount Of Aileron input required about 1/8 of an inch or less effective difference between the two wings would probably do it. It doesnt look like there is any adjustment for this as there is on some cessnas that have a cam for adjusting the Angie of attack. Without making some careful measurements it would be hard to establish that this is the case.

Ben
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  #4  
Unread 12-22-16, 10:01 PM
Kim Geyer Kim Geyer is offline
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You might have a mechanic check the rigging with the Robertson STOL manual. It says to rig the flaps per the cessna manual. then with the control lock in rig the left aileron to fair with the tip and the right aileron @ 1/4 inch above the tip.
Kim

Last edited by Kim Geyer : 12-23-16 at 11:52 AM.
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  #5  
Unread 12-25-16, 12:36 PM
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cessnadriver cessnadriver is offline
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Level flight requires slight right hand turn input

I have seen this in other Cessnas. My C172 had the problem, although this Cessna has the eccentric bushings in the trailing edge of each wings. I adjusted the left (LIGHT WING) full down and the right full up. I KNOW THIS ISN'T THE PROBLEM YOU MENTION, BUT LET ME FINISH MY EXPLANATION. After all these adjustments my IA noticed my left flap was NOT fully UP in the tract. I replaced the flap and plane flys straight! So my advice is to make certain that your flaps (on the high flying wing) is in FULL UP position.
FYI.
BILLS
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  #6  
Unread 12-27-16, 05:01 PM
B2C2 B2C2 is offline
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I will definitely check the Robertson manual for that aileron setting. 1/4 inch of upward deflection on the right aileron would probably fix most of whats going on. I have the manual but its currently at the shop with the plane and log books. In regard to the flap suggestion I have looked pretty carefully at the flap positions and they seem to be even on both sides.
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