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|
Attributes | |
ACN | 868269 |
Time | |
Date | 200912 |
Local Time Of Day | 1201-1800 |
Place | |
Locale Reference | ZZZ.Airport |
State Reference | US |
Environment | |
Light | Daylight |
Aircraft 1 | |
Make Model Name | B737-400 |
Operating Under FAR Part | Part 91 |
Flight Phase | Parked |
Component | |
Aircraft Component | Flap Control (Trailing & Leading Edge) |
Person 1 | |
Qualification | Maintenance Inspection Authority Maintenance Airframe Maintenance Powerplant |
Experience | Maintenance Lead Technician 26 Maintenance Technician 34 |
Events | |
Anomaly | Deviation - Procedural Published Material / Policy Deviation - Procedural MEL |
Narrative:
A B737-400 was maintenance ferried from ZZZ to ZZZ1 for the purpose of repair to a problem with the flap system. The problem was that the flaps would not extend past 30 units. This was a repeat write-up. ZZZ2 maintenance control directed the contract mechanic in the completion on the required paperwork. The ferry permit allows the aircraft to fly with a known defect. The contract mechanic completed the paperwork to release the aircraft for the intended ferry flight. Because of the history of the write-up maintenance control directed the contract technician to pull and collar the (flap) load relief circuit breaker (circuit breaker). This action was taken to prevent 'secondary damage.' however; existing maintenance relief via the use of an MEL was not used. Use of the MEL would have restricted the aircraft's maximum flaps to 30 units. There were no listed limitations to the ferry permit. In ZZZ1; we conducted the maintenance per a company issued request. The goal was to effect repairs for the purposes of conducting a test flight. We complied with the repair request which included additional items added due to my personal experience. Since we did not have a confirmed failure; the test flight was scheduled to see if the problem could be duplicated. Besides my role in directing the repairs; I signed both the company request and ferry flight deferral releasing the aircraft for a test flight. Upon conducting the test flight it was discovered by the flight crew that load limit system did not work. The aircraft returned to ZZZ1. After landing the maintenance crew discovered the reason for the load limit malfunction was that the circuit breaker that had been pulled and collared for the original ferry flight was still pulled and collared after maintenance. After resetting the circuit breaker; the load limit system performed as designed on a second test flight. The error was a failure to reset the circuit breaker before returning the aircraft to service for it's test flight. The mitigating factor was 'fatigue.' I had worked over 16 hrs prior to completing the paperwork. Failure of maintenance control to put the circuit breaker deferral on a second log page and failure of maintenance control to remind me that secondary maintenance had been conducted for safety.
Original NASA ASRS Text
Title: A Lead Mechanic reports that after trouble shooting a repeat Flight Crew write-up for a B737-400 with flaps that would not go past 30; Mechanics found Trailing Edge Flap Jackscrew Gimbal Nuts were riding high on the Jackscrew threads and even appeared to be sliding over the Jackscrew threads when they applied a load to the Flap Trailing Edges.
Narrative: A B737-400 was maintenance ferried from ZZZ to ZZZ1 for the purpose of repair to a problem with the flap system. The problem was that the flaps would not extend past 30 units. This was a repeat write-up. ZZZ2 Maintenance Control directed the Contract Mechanic in the completion on the required paperwork. The ferry permit allows the aircraft to fly with a known defect. The Contract Mechanic completed the paperwork to release the aircraft for the intended ferry flight. Because of the history of the write-up Maintenance Control directed the Contract Technician to pull and collar the (flap) Load Relief Circuit Breaker (CB). This action was taken to prevent 'secondary damage.' However; existing maintenance relief via the use of an MEL was not used. Use of the MEL would have restricted the aircraft's maximum flaps to 30 units. There were no listed limitations to the ferry permit. In ZZZ1; we conducted the maintenance per a company issued request. The goal was to effect repairs for the purposes of conducting a test flight. We complied with the repair request which included additional items added due to my personal experience. Since we did not have a confirmed failure; the test flight was scheduled to see if the problem could be duplicated. Besides my role in directing the repairs; I signed both the company request and ferry flight deferral releasing the aircraft for a test flight. Upon conducting the test flight it was discovered by the flight crew that Load Limit System did not work. The aircraft returned to ZZZ1. After landing the maintenance crew discovered the reason for the load limit malfunction was that the CB that had been pulled and collared for the original ferry flight was still pulled and collared after maintenance. After resetting the CB; the Load Limit System performed as designed on a second test flight. The error was a failure to reset the CB before returning the aircraft to service for it's test flight. The mitigating factor was 'fatigue.' I had worked over 16 hrs prior to completing the paperwork. Failure of Maintenance Control to put the CB deferral on a second Log page and failure of Maintenance Control to remind me that secondary maintenance had been conducted for safety.
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.