Ed_Wischmeyer
Well Known Member
For the past six months, I've been dealing with an intermittent electric elevator trim problem cleverly masquerading as an autopilot problem -- when the electric trim would stick after disconnecting the autopilot (a misleadingly truncated version of the scenario), the cure was to cycle power to the autopilot servos. But today, I finally had a hard failure (fortunately, on the ground) and the problem was easy to find, especially when you could hear the elevator trim servo motor running and see that the trim tab wasn't moving. A stripped gear.
So this got me to thinking... probably most all of us learned to fly in factory built airplanes where electric trim, if installed, was an adjunct to the manual trim, so electric elevator trim failure was of little consequence and not taught. And in transport category aircraft, the concern is runaway trim, so I've always made sure in my airplanes that there was a way to power down the electric trim if it decided to get frisky spontaneously.
And when I think of total electrical failure symptoms in homebuilts, I've always thought about attitude information, a standby GPS, electronic ignition, and flaps -- but I've never thought seriously about the effects of stuck elevator trim, like you would get in an electrical failure.
So... Has anybody ever practiced landing an RV with a simulated failed elevator trim, like, stuck at cruise setting? Or done a full circuit with lots of nose up trim, like you'd have on landing?
For all you CFIs and checkout pilots, do you teach elevator trim failure? Any thoughts or comments?
Thanks,
Ed
So this got me to thinking... probably most all of us learned to fly in factory built airplanes where electric trim, if installed, was an adjunct to the manual trim, so electric elevator trim failure was of little consequence and not taught. And in transport category aircraft, the concern is runaway trim, so I've always made sure in my airplanes that there was a way to power down the electric trim if it decided to get frisky spontaneously.
And when I think of total electrical failure symptoms in homebuilts, I've always thought about attitude information, a standby GPS, electronic ignition, and flaps -- but I've never thought seriously about the effects of stuck elevator trim, like you would get in an electrical failure.
So... Has anybody ever practiced landing an RV with a simulated failed elevator trim, like, stuck at cruise setting? Or done a full circuit with lots of nose up trim, like you'd have on landing?
For all you CFIs and checkout pilots, do you teach elevator trim failure? Any thoughts or comments?
Thanks,
Ed
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