8KCAB Elevator Trim question / problem?

[jpfli]

I have a 98 8KCAB.

Recently on a 1.5 hour cross country flight I noticed I had to keep adding nose down trim.

The aircraft was placed in a level flight attitude with power set at 24 squared. Elevator trim was adjusted to relieve all stick pressure.

A short while later, forward stick pressure had to be added to maintain level flight. Trim was again used to relieve control pressure so the aircraft would fly hands off.

This would repeat itself every 5 - 10 minutes. It felt like i was in a constant for-next loop.

What must be done to fix this problem?

Regards,
John

 

[Tom]

John-

Remove the trim knob and plastic quadrant cover, taking care not to drop the wrench (you might tie a strign to it) you can slightly increase the friction on the trim lever nut.

Tom-

 

[luvaraair]

As Tom said, it's most likely the nut on your trim level. The only other problem I've had with the trim creeping, was with the turnbuckle on the trim tab not being tensioned enough, and cable tended to sag a little bit.

Chris

 

[jerrymjr]

The friction is normally applied via a leather washer. Obviously the washer (being made of natural things) can lose its 'stick' over time. You should be able to tighten the nut a tweak to tighten things back up.