Citation down in Milwaukee,

[BushwickBill]

Ahh it was a C550. They all have a manual trim wheel next to the pilots right knee. It also has a BIG RED trim/AP Disconnect button on the yoke.

Yeah but will the trim disconnect on the yoke stop a runaway trim event? I'm assuming you need to pull the breaker to stop that.

The red button disconects the autopilot and the yaw damp, at least on the CJ2

 

[stratman560]

Yeah but will the trim disconnect on the yoke stop a runaway trim event? I'm assuming you need to pull the breaker to stop that.

The red button disconects the autopilot and the yaw damp, at least on the CJ2

From Page 5E9 from the Simuflite Initial Pilot Training Manual for the II/SII:

The AP/TRIM disconnect switch on the pilot and copilot's yoke electrically disables the electric trim if a malfunction in electric trim should occur. Pulling the 5 amp PITCH TRIM CB on the left circuit breaker panel removes power from the electric trim motor.

This still left me with a few questions so furthermore;

From Page 5E19:

Electric Elevator Trim Failure / Runaway Trim

If an electric elevator trim runaway occurs, press and hold the AP/TRIM disconnect switch on the pilot's or copilot's control wheel. The switch removes electrical power and stops movement of the electric trim. Remove electrical power to the elevator trim system by pulling the PITCH TRIM CB. After removing power to the electric trim motor, release the AP/TRIM disconnect switch. Continue the flight using manual elevator trim.

Also, PITCH TRIM CB is located on the Captain's Side CB Panel, bottom row, sixth from the left side, fourth from the right. The CB panel layouts changed after S/N 626, the accident aircraft was S/N 246.


Personally, I'm having a hard time believing it was runaway trim. Hold the big red button, pull the plug on the CB, problem solved for the time being. Oh well, I guess the NTSB will take it from here and start looking at maintenance, tapes, etc. Godspeed.

 

[Say Again Over]

Has anyone checked links for ATC conversation?

 

[blzr]

From Page 5E9 from the Simuflite Initial Pilot Training Manual for the II/SII:

The AP/TRIM disconnect switch on the pilot and copilot's yoke electrically disables the electric trim if a malfunction in electric trim should occur. Pulling the 5 amp PITCH TRIM CB on the left circuit breaker panel removes power from the electric trim motor.

This still left me with a few questions so furthermore;

From Page 5E19:

Electric Elevator Trim Failure / Runaway Trim

If an electric elevator trim runaway occurs, press and hold the AP/TRIM disconnect switch on the pilot's or copilot's control wheel. The switch removes electrical power and stops movement of the electric trim. Remove electrical power to the elevator trim system by pulling the PITCH TRIM CB. After removing power to the electric trim motor, release the AP/TRIM disconnect switch. Continue the flight using manual elevator trim.

Also, PITCH TRIM CB is located on the Captain's Side CB Panel, bottom row, sixth from the left side, fourth from the right. The CB panel layouts changed after S/N 626, the accident aircraft was S/N 246.


Personally, I'm having a hard time believing it was runaway trim. Hold the big red button, pull the plug on the CB, problem solved for the time being. Oh well, I guess the NTSB will take it from here and start looking at maintenance, tapes, etc. Godspeed.

All true, and also, the electric trim CB is located by the pilots left hand, and should be collard for easy identification.

 

[Nick5600]

Likely scenario

My guess is the autopilot was engaged at the time of the runaway. In a 550 the autopilot will hold it as long as possible. If your quick you might see a autopilot torque light. Once to much torque is put on the autopilot it will disconnect itself. At 2000 ft agl the pilot wouldn't have much time to react to this. When the autopilot kicked itself off the pilot would have a heck of a time controlling it. Anyhow godspeed to the crew, and I'm happy to hear the patient got a new set lungs!

 

[WMUSIGPI]

All true, and also, the electric trim CB is located by the pilots left hand, and should be collard for easy identification.

That CB was NOT collared in that airplane.

 

[mynameisjim]

Funny how important CBs like those are often mixed in with RT PITOT HEAT and AFT LAV FAN and not in some easy to remember position, like A1. I mean why does it always have to be somewhere like row 2, 6 from the left.

 

[WTF]

Yes

My guess is the autopilot was engaged at the time of the runaway. In a 550 the autopilot will hold it as long as possible. If your quick you might see a autopilot torque light. Once to much torque is put on the autopilot it will disconnect itself. At 2000 ft agl the pilot wouldn't have much time to react to this. When the autopilot kicked itself off the pilot would have a heck of a time controlling it. Anyhow godspeed to the crew, and I'm happy to hear the patient got a new set lungs!

I had a similar event in a Lear 31. The auto pilot was counteracting the trim until the forces become to great, then out of nowhere it disconnects and you are on your own to figure out why it did, what is happening, what to do to correct it. It can be a major overload that happens in seconds. Any word on the other 2 Citation accidents. I heard this is the 3rd in a month.

 

[airplane wizard]

My guess is the autopilot was engaged at the time of the runaway. In a 550 the autopilot will hold it as long as possible. If your quick you might see a autopilot torque light. Once to much torque is put on the autopilot it will disconnect itself. At 2000 ft agl the pilot wouldn't have much time to react to this. When the autopilot kicked itself off the pilot would have a heck of a time controlling it.

Doesn't the ap use the pitch trim for elevator control? How would the ap compensate for a pitch trim run away?

 

[Paladin]

Just got my alumni magazine today in the mail and realized that I went to college with one of the doctors on that Citation. Not sure if I ever had a chance to meet him though. A terrible tragedy.