Positive Control pulls left

[SpamPilot]

When I got my M20F 50 hours ago, the Positive Control (PC) system worked great.  Love it.  But it seems to be developing an increasing tendency to turn left.  I can zero this out with the roll trim knob in the panel, but now the roll trim knob is cranked over to the right quite a ways.  It's not rigging because when I press the button to defeat the system, the plane tracks straight and level hands off.  The turn coordinator appears to be functioning normally.  The Brittain user manual says the roll trim knob might need to be turned as much as 90 degrees off center to straighten the plane and they still consider it normal operation, so maybe this is "normal", but I think I'm getting past the 90 degree point.  Anyone else have this happen to them or have any ideas?

[FAST FLIGHT OPTIONS LLC]

Time to overhaul the roll trim servo possibly?

[Piloto]

You have a leak. Check the PC hoses and aileron servo boots. The servo boots in particular need to be replaced about every ten years.

 

José

[tony]

Time to overhaul the roll trim servo possibly?

what's a roll trim servo?

[Hank]

My plane began turning left. After checking the other three servos (two in the ELT compartment, and the right wing), it turned out to be a torn boot on the left wing servo. At least I know the two for the tail are good, and I rewrapped the right servo. Wing servos are behind the inspection panel at the inboard end of each aileron, but you will need small hands and stubby wrenches to get the single screw out of the back of the servo.

Google Brittain Industries, Tulsa, OK, an d call them. It is simple to rewrap, they will tell you what you need and how to do it. If it's torn, they will fix it quickly and inexpensively. Last December it took about two weeks including shipping, and their charge was about $125 to fix my left wing servo.

Good luck with your repairs. It's really nice to fly straight again!