Power trim emergency advice

[gereed75]

I used a two part approach to mitigate risk:

1) I “biased” the servo/tab linkage by lengthening the threaded rod so that the servo provides just enough nose down trim to balance flight at Vne, no more is possible as the servo is at its physical limit. My reasoning was that a nose up runaway was a less dire situation, as a simple reduction in power would result in rapidly decreasing airspeed in a runaway induced climb, and as AS slows, stick force could easily overcome trim force.

2) install the TCW controller set on slow speed - trim operation is slow in some regimes, but certainly adequate.

I have a trim disable switch, but was not confident in my response diagnosis time in an extremis situation

Give it a real world test. See what you think

[gmcjetpilot]

I think this question might be prompted by the recent trim issues with 737 MAX. Jets, entire horizontal stab moves, not a tab on the elevator.

The trim tab on an RV elevator can't make plane uncontrollable but could create high control forces at high speeds. Slowing down and man handling it will work.

[Mconner7]

Originally Posted by gmcjetpilot

I think this question might be prompted by the recent trim issues with 737 MAX. Jets, entire horizontal stab moves, not a tab on the elevator.

The trim tab on an RV elevator can't make plane uncontrollable but could create high control forces at high speeds. Slowing down and man handling it will work.

And if my pitot ices over, the minimum speed function on the G3 autopilot try?s to do an outside loop like the Max 8.