|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||airport : zzz.airport|
|Altitude||agl single value : 0|
|Operator||common carrier : air carrier|
|Make Model Name||B737-400|
|Operating Under FAR Part||Part 121|
|Affiliation||company : air carrier|
|Function||maintenance : technician|
|Affiliation||company : air carrier|
|Anomaly||aircraft equipment problem : critical|
maintenance problem : improper maintenance
non adherence : far
non adherence : published procedure
|Independent Detector||aircraft equipment other aircraft equipment : stab trim wheel lock|
other other : 3
|Resolutory Action||none taken : detected after the fact|
|Consequence||faa : investigated|
|Maintenance||contributing factor : work cards|
contributing factor : manuals
performance deficiency : scheduled maintenance
performance deficiency : non compliance with legal requirements
|Problem Areas||Maintenance Human Performance|
Chart Or Publication
|Primary Problem||Maintenance Human Performance|
First time completing task from start to finish. One other time doing this task was the installation only. Mechanics involved were myself and mr X. I was in charge of setting up the cockpit to accomplish the task. During accomplishing the task for inspecting the horizontal stabilizer center section hinge pins; which required the removal of the pin; we were approached by the FAA and as why the stabilizer trim lock was not installed. I informed the FAA inspector that by following the procedure in the maintenance manual; that the lock did not fit on the trim wheel. I had set the stabilizer to the maximum leading edge down position; to gain access to the pins; using the electrical trim switches on the pilot's control column. The trim lock was nearby the trim wheel but not installed. I had pulled and 'danger' tagged the circuit breakers for actuation of the stabilizer trim motor and felt that it was safe to continue with the task. We were the only ones working on the aircraft at the time and felt that no one would be actuating the controls. The task card does not address not having installing the stabilizer trim lock.
Original NASA ASRS Text
Title: A B737-400 DURING A HORIZ STABILIZER CTR SECTION HINGE PIN INSPECTION; AN FAA SAFETY INSPECTOR QUESTIONED WHY THE STABILIZER TRIM WHEEL LOCKOUT WAS NOT INSTALLED.
Narrative: FIRST TIME COMPLETING TASK FROM START TO FINISH. ONE OTHER TIME DOING THIS TASK WAS THE INSTALLATION ONLY. MECHS INVOLVED WERE MYSELF AND MR X. I WAS IN CHARGE OF SETTING UP THE COCKPIT TO ACCOMPLISH THE TASK. DURING ACCOMPLISHING THE TASK FOR INSPECTING THE HORIZ STABILIZER CTR SECTION HINGE PINS; WHICH REQUIRED THE REMOVAL OF THE PIN; WE WERE APCHED BY THE FAA AND AS WHY THE STABILIZER TRIM LOCK WAS NOT INSTALLED. I INFORMED THE FAA INSPECTOR THAT BY FOLLOWING THE PROC IN THE MAINT MANUAL; THAT THE LOCK DID NOT FIT ON THE TRIM WHEEL. I HAD SET THE STABILIZER TO THE MAX LEADING EDGE DOWN POS; TO GAIN ACCESS TO THE PINS; USING THE ELECTRICAL TRIM SWITCHES ON THE PLT'S CTL COLUMN. THE TRIM LOCK WAS NEARBY THE TRIM WHEEL BUT NOT INSTALLED. I HAD PULLED AND 'DANGER' TAGGED THE CIRCUIT BREAKERS FOR ACTUATION OF THE STABILIZER TRIM MOTOR AND FELT THAT IT WAS SAFE TO CONTINUE WITH THE TASK. WE WERE THE ONLY ONES WORKING ON THE ACFT AT THE TIME AND FELT THAT NO ONE WOULD BE ACTUATING THE CTLS. THE TASK CARD DOES NOT ADDRESS NOT HAVING INSTALLING THE STABILIZER TRIM LOCK.
Data retrieved from NASA's ASRS site as of January 2009 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.