CRJ900 first officer experiences uncommanded stabilizer trim movement during preflight and during th...

Narrative:

After a prior flight on this same aircraft; and following a layover of about one hour we were to take this same aircraft back out. After power initialization; the trims were noted to be in the green. After some time spent with preflight duties; it was noted that the trims were once again out of the green range. A comment was made to this effect; and the trims reset to the green and centered position. After the power push; we initiated the flight as normal. The trims were checked to be in the green on the before takeoff check by both crew members. The takeoff configuration also checked as okay in the before takeoff checklist. The runway was taken and the takeoff initiated. No aural warnings or cautions were present as the power was brought up as would occur with a miss set trim. After the roll was initiated; the configuration warning sounded at 75 KTS and an abort was called and initiated. Additionally; after consulting maintenance control; the aircraft was taken out to test the trims on the ground again and it was found that even after setting them in the green; they went white for no reason; and then failed to move at all. A high speed taxi on the runway was also done without a repeat warning; but during taxi in the trims moved on their own and out of the green once again. It was also found that this same malfunction occurred 10 or so days previous to this occurrence and was cleared by maintenance. With this being a second occurrence; this seems to be a repeat issue and of concern with this aircraft.this warning and abort occurred due to a mechanical failure. The procedures and training were followed and resulted in a safe aborted takeoff. The trims were checked 4 times prior to the warning; prior to push; on before takeoff check; configuration check; then automatically with engines above 70% all with no error. Malfunction occurred at 75 KTS.

Original NASA ASRS Text

Title: CRJ900 First Officer experiences uncommanded stabilizer trim movement during preflight and during the takeoff roll. Takeoff is aborted when takeoff warning sounds. Aircraft had a short history of uncommanded trim movement.

Narrative: After a prior flight on this same aircraft; and following a layover of about one hour we were to take this same aircraft back out. After power initialization; the trims were noted to be in the green. After some time spent with preflight duties; it was noted that the trims were once again out of the green range. A comment was made to this effect; and the trims reset to the green and centered position. After the power push; we initiated the flight as normal. The trims were checked to be in the green on the before takeoff check by both crew members. The takeoff configuration also checked as okay in the before takeoff checklist. The runway was taken and the takeoff initiated. No aural warnings or cautions were present as the power was brought up as would occur with a miss set trim. After the roll was initiated; the configuration warning sounded at 75 KTS and an abort was called and initiated. Additionally; after consulting Maintenance Control; the aircraft was taken out to test the trims on the ground again and it was found that even after setting them in the green; they went white for no reason; and then failed to move at all. A high speed taxi on the runway was also done without a repeat warning; but during taxi in the trims moved on their own and out of the green once again. It was also found that this same malfunction occurred 10 or so days previous to this occurrence and was cleared by Maintenance. With this being a second occurrence; this seems to be a repeat issue and of concern with this aircraft.This warning and abort occurred due to a mechanical failure. The procedures and training were followed and resulted in a safe aborted takeoff. The trims were checked 4 times prior to the warning; prior to push; on before takeoff check; configuration check; then automatically with engines above 70% all with no error. Malfunction occurred at 75 KTS.

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	900292
Time
Date	201007
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet 900 (CRJ900)
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Component
Aircraft Component	Horizontal Stabilizer Trim
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial
Experience	Flight Crew Last 90 Days 23 Flight Crew Total 1500 Flight Crew Type 500
Events
Anomaly	Aircraft Equipment Problem Critical

CRJ900 first officer experiences uncommanded stabilizer trim movement during preflight and during the takeoff roll. Takeoff is aborted when takeoff warning sounds. Aircraft had a short history of uncommanded trim movement.