Nice job Mark. You handled it like the professional you are.

That did not happen to me when I declared and diverted for an engine low on oil causing prop problems (Cessna T210).

Only follow up was a local, not FAA, guy who came by the shop to see what was up. No paperwork.

Not telling the controller about your problem was not prudent. At the very least, you could have crashed and vital information about your problem, perhaps something that saves someone else in the future, could have been lost if not relayed to ATC. ATC may be able to summon useful help, say in the form of another Citation pilot to give some advice.


Bad idea, people die from that. For example, Alaska Air 261. They played with the pitch until it failed.

If you suspect a control problem, and the plane is flyable, don't touch it and land ASAP. You are better off with a flyable airplane than the very real chance you make it worse.

The pitch trim system is the most dangerous flight control in the airplane. It can put the plane into a state that overpowers the pilot.

Mike C.

Fixed stabilizer, trim tab on back of elevator actuated mechanically.

Mike C.

They are replacing the trim motor. The clutch wasn't releasing and slip clutch wasn't slipping. This was a 3 minute phone call. Will find out more later.

When I was younger and more bulletproof, a sistership PA32 crashed with 6 POB. Cause: defective trim switch causing pitch trim runaway. Since then all switches were replaced with dual-pole switches. When I check out a new pilot, I show how to stop the pitch trim in all possible ways, including switching off the master if it needs to be.

Really nice job Mark. Scary real scary. Glad you had a great result.

Do the jet checklists have checking the elevator trim for freedom to manually adjust even with thumb motor in on "position"? After start the TBM has the two "pole" switch with left depressed we check the trim wheel to see if we can over power the motor.

The desert arrival is also used for PHX. It's a high traffic area with airlines going into PHX. Also they cram planes pretty tight into SDL. Declaring emergency would let ATC give you more space in case things got worse.

That's pretty much the same with the 525. I was taught in my initial to disregard what Cessna says.

If the AP is holding and the out of trim light alluminates leave the AP in.
Pull the CB for the trim.
Try to then trim out the force.
Then disconnect AP.

Seems logical to me.

Andrew

That's pretty much the same with the 525. I was taught in my initial to disregard what Cessna says.

If the AP is holding and the out of trim light alluminates leave the AP in.
Pull the CB for the trim.
Try to then trim out the force.
Then disconnect AP.

Seems logical to me.

Andrew

Whew, glad it didn't fail full up or down. Any idea how frequently failures such as these occur? On SIC interviews, good reason to check knees

For all you know prior to disconnect, the AP was the cause of the problem. I wouldn't hesitate to take it out of the system and then YOU can judge what the plane is doing.

Also note that the autopilot CANNOT put as much force into the controls as a human.


Wait, you were using both the autopilot AND hand flying it at the same time?

That's generally very bad because the force you, the human pilot, puts into the system is something the autopilot senses as aerodynamic load and it will trim AGAINST that force. In other words, the AP will wind up the trim and fight you.

There have been accidents where a human pilot did not realize the AP was engaged and they fought the controls all the while the AP was winding up the trim against them. This is particularly true of AP control heads on center pedestals as something can fall, push their button, and the pilot is unaware. AP engagement can also happen due to circuit fault in the logic.

Whenever you have a control problem, be sure to press the AP disconnect button EVEN IF YOU NEVER ENGAGED THE AP.

Mike C.

Let me addess my concern about disconnecting my AP with a known trim problem. See this thread viewtopic.php?f=7&t=91201&hilit=Snapped+trim

Net net on an ILS in IMC. all good. I saw exactly the same thing as in the Citation: a trim command that should be handled by the auto trim system. In this case (Cessna 310) I disconnected the AP and it turned into a goat rodeo in IMC on an ILS. Rightly or wrongly I never forgot this so it is the root of my concern about disconnecting AP on the Citation with a known trim issue. Would it too become a rodeo? It was a concern.

Remember by the time I disconnected the AP in the Citation the trim CB was pulled. It required both hands and some knee for relief to keep it from climbing. I rengaged the AP and the control pressures were less but still required my input . Not a worry about the AP trying to fight me because the trim was disconnected. My control pressures became the trim. It worked.

When will your airplane be back in action? We need some more video shenanigans.

While I agree with Mike that it's generally best to kill the entire autopilot/trim system if it's acting abnormally, removing autotrim from the equation by pulling its breaker isn't a bad idea either and that has the potential to let Otto keep the plane centered on the correct course while you fight with pitch. But to me the biggest downside to leaving the pitch axis active during an approach with a pitch control issue is that you could easily end up with a rapid pitch down at a very low altitude when you finally disconnect the system. Personally I'd rather deal with that up higher.

The Citation is back in action. Simcom next week for SPE recurrent. Might work on trim failure stuff. Good news is that I have a made it a point to let my SIMCOM instructors fly SIC with me in the airplane. Since they know I am "safe" maybe we can spend more time working on nuanced things. Or that's my hope anyway

I will have a couple shenanigans trips later in the month. One involving "non pilot " again. She says she is ready to try again.

She saw the meltdown video. Said it gave her anxiety all over again. She indicated the aural alerts and warnings were more than she could handle. Thought it meant the airplane was going to crash. The broken intercom made it worse because she couldn't communicate. She indicated I looked worried. That's her preception and her reality. Now that she has a baseline I hope the next trip is better. Vegas and t ride Presidents day weekend. moral to the story is "brief the passengers".

Here we are at the inaugural ball and here she is on the cover of the Bad Girls reality show