Jetstar captain reports jammed stabilizer trim during descent. All attempts at regaining control of ...

Narrative:

We were descending from FL380; passing through FL280; airspeed indicating 280 KTS. I was trying to increase the rate of descent and noticed that the autopilot was not allowing me to change pitch. Advised the copilot that I was going to disengage the autopilot & be ready for a sudden pitch change. With both hands on the yoke; I disengaged the autopilot & had an immediate pitch up. I attempted to trim nose down but there was no response from the primary electric trim. Advised the first officer to get the emergency checklist out & go to trim failure checklist. We disengaged primary trim; switched to emergency trim. No response. We tried resetting both trims with no response. We completed the checklist for landing; trim inoperative at 2.8 degrees. We shifted our passengers to the rear for better control. Procedure called for a zero flap landing. Both pilots were holding the yoke back. Stabilized approach requires about 25 pounds of backpressure and another 10 for the flare. Landing on 10;000 ft runway was smooth and required no further assistance. Once we were on the ramp I checked the trims. Both trims were functioning again. Maintenance inspected the pitch trim actuator. Water had entered through a seal; displacing much of the lubricating oil. Apparently; in the descent; the water froze; jamming the horizontal stabilizer in its current position.

Original NASA ASRS Text

Title: Jetstar Captain reports jammed stabilizer trim during descent. All attempts at regaining control of stabilizer trim were unsuccessful and the crew landed with zero flaps at destination. Stabilizer trim was found to function normally once on the ground.

Narrative: We were descending from FL380; passing through FL280; airspeed indicating 280 KTS. I was trying to increase the rate of descent and noticed that the autopilot was not allowing me to change pitch. Advised the Copilot that I was going to disengage the autopilot & be ready for a sudden pitch change. With both hands on the yoke; I disengaged the autopilot & had an immediate pitch up. I attempted to trim nose down but there was no response from the primary electric trim. Advised the First Officer to get the emergency checklist out & go to Trim Failure checklist. We disengaged primary trim; switched to emergency trim. No response. We tried resetting both trims with no response. We completed the checklist for landing; trim inoperative at 2.8 degrees. We shifted our passengers to the rear for better control. Procedure called for a zero flap landing. Both pilots were holding the yoke back. Stabilized approach requires about 25 LBS of backpressure and another 10 for the flare. Landing on 10;000 FT runway was smooth and required no further assistance. Once we were on the ramp I checked the trims. Both trims were functioning again. Maintenance inspected the pitch trim actuator. Water had entered through a seal; displacing much of the lubricating oil. Apparently; in the descent; the water froze; jamming the horizontal stabilizer in its current position.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	850819
Time
Date	200909
Local Time Of Day	1801-2400
Place
Locale Reference	OAK.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Jetstar 1329 (C140)
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Elevator Trim System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 6748 Flight Crew Type 1095
Events
Anomaly	Aircraft Equipment Problem Critical

Jetstar captain reports jammed stabilizer trim during descent. All attempts at regaining control of stabilizer trim were unsuccessful and the crew landed with zero flaps at destination. Stabilizer trim was found to function normally once on the ground.