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|
Attributes | |
ACN | 828235 |
Time | |
Date | 200903 |
Local Time Of Day | 0601-1200 |
Place | |
Locale Reference | SFO.Airport |
State Reference | CA |
Aircraft 1 | |
Make Model Name | B747-400 |
Operating Under FAR Part | Part 121 |
Flight Phase | Parked |
Flight Plan | IFR |
Person 1 | |
Function | Captain Pilot Flying |
Experience | Flight Crew Last 90 Days 240 Flight Crew Total 16000 Flight Crew Type 3000 |
Events | |
Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Maintenance |
Narrative:
I am writing this report to bring to your attention what I believe to be potentially illegal and unsafe maintenance action and procedures. Approximately 24 hours prior to the flight; as is my normal practice; I checked the maintenance status of the aircraft that was planned for our flight. I noticed a deferral for the landing gear latch solenoid. The original problem was a gear disagree EICAS advisory message; indicating that the gear was not in the selected position. The crew reported that the gear could not be raised normally; the handle was locked and could not be raised beyond the 'off' (middle) position. The crew recycled the gear but still could not raise the gear without engaging the 'gear override' system. Maintenance subsequently deferred the landing gear latch solenoid; which allowed the aircraft to continue. The MEL item card associated with this deferral instructs the crew to retract the landing gear using the flight manual irregular procedure. The aircraft has been flying around in this condition without any documented maintenance action. Discussion with system maintenance on the day prior to the flight; I called system maintenance to discuss this problem about 16 hours prior to the flight and asked the following: 1) the basis for the deferral of the landing gear latch solenoid; 2) what troubleshooting had been done and what was planned to be done; 3) about any safety implications surrounding the deferral; and 4) what backup systems were available to the crew in the event that a subsequent failure would cause the gear disagree EICAS message to appear. He did not know the basis for the specific reason for deferring the latch solenoid and was unaware of any troubleshooting that had been performed. We discussed the potential problems that might result as a result of the crew forcing the retraction of the landing gear if the tilt mechanism were to fail. Time and parts available but still no troubleshooting. Upon arrival at the airport this morning; I called system maintenance through dispatch to discuss the deferral. All involved were surprised that the issue had not been addressed. No action on this item was performed overnight; as I was told would be the case. This deferral occurred in march/2009. Up to now; there have been several opportunities to troubleshoot the problem but none has been done; according to the maintenance controller. Parts have been available in ZZZ since march/2009 according to maintenance computer log. The maintenance controller was astonished himself that no troubleshooting had been done to date. I discussed this problem with my crew; and we all remained very concerned about the potential safety implications of the deferral; and secondarily; the basis for the deferral itself and the lack of any maintenance action since the original in march/2009. With dispatch and maintenance concurrence; we made a plan to go out to the aircraft and discuss the problem with maintenance. I wanted to know why the landing gear latch solenoid was deferred and what troubleshooting had been accomplished. If we could be assured that the latch solenoid was; in fact; at fault; I told dispatch and maintenance that I would accept it. We went to the aircraft and I spoke with a line mechanic and the maintenance supervisor. Neither could answer either of my questions. No troubleshooting had been done ('no parts;' not true according to maintenance computer log); the gear had not been 'slugged' (sensors tested). The mechanic also told us that he thought that the gear sensors were at fault. However; this was not what was deferred. The maintenance supervisor also tried to convince us that the fault had not recurred. His basis for this was that no subsequent write-ups had been made. I tried; unsuccessfully; to explain to him that crews are not required; and rarely do; write up items that already have been deferred and; thus; we have no idea whether or not the fault has recurred. Aircraft refusal as a result of not being able to
Original NASA ASRS Text
Title: B747-400 Captain refused the aircraft assigned to his flight because of long term deferral of landing gear retraction mechanism requiring the routine use of an irregular procedure to retract the landing gear.
Narrative: I am writing this report to bring to your attention what I believe to be potentially illegal and unsafe maintenance action and procedures. Approximately 24 hours prior to the flight; as is my normal practice; I checked the maintenance status of the aircraft that was planned for our flight. I noticed a deferral for the landing gear latch solenoid. The original problem was a Gear Disagree EICAS advisory message; indicating that the gear was not in the selected position. The crew reported that the gear could not be raised normally; the handle was locked and could not be raised beyond the 'off' (middle) position. The crew recycled the gear but still could not raise the gear without engaging the 'Gear Override' system. Maintenance subsequently deferred the landing gear latch solenoid; which allowed the aircraft to continue. The MEL item card associated with this deferral instructs the crew to retract the landing gear using the Flight Manual Irregular Procedure. The aircraft has been flying around in this condition without any documented maintenance action. Discussion with System Maintenance on the day prior to the flight; I called System Maintenance to discuss this problem about 16 hours prior to the flight and asked the following: 1) the basis for the deferral of the landing gear latch solenoid; 2) what troubleshooting had been done and what was planned to be done; 3) about any safety implications surrounding the deferral; and 4) what backup systems were available to the crew in the event that a subsequent failure would cause the Gear Disagree EICAS message to appear. He did not know the basis for the specific reason for deferring the latch solenoid and was unaware of any troubleshooting that had been performed. We discussed the potential problems that might result as a result of the crew forcing the retraction of the landing gear if the tilt mechanism were to fail. Time and parts available but still no troubleshooting. Upon arrival at the airport this morning; I called System Maintenance through dispatch to discuss the deferral. All involved were surprised that the issue had not been addressed. No action on this item was performed overnight; as I was told would be the case. This deferral occurred in March/2009. Up to now; there have been several opportunities to troubleshoot the problem but none has been done; according to the Maintenance Controller. Parts have been available in ZZZ since March/2009 according to Maintenance Computer Log. The Maintenance Controller was astonished himself that no troubleshooting had been done to date. I discussed this problem with my crew; and we all remained very concerned about the potential safety implications of the deferral; and secondarily; the basis for the deferral itself and the lack of any maintenance action since the original in March/2009. With dispatch and maintenance concurrence; we made a plan to go out to the aircraft and discuss the problem with maintenance. I wanted to know why the landing gear latch solenoid was deferred and what troubleshooting had been accomplished. If we could be assured that the latch solenoid was; in fact; at fault; I told dispatch and maintenance that I would accept it. We went to the aircraft and I spoke with a Line Mechanic and the Maintenance Supervisor. Neither could answer either of my questions. No troubleshooting had been done ('no parts;' not true according to Maintenance Computer Log); the gear had not been 'slugged' (sensors tested). The Mechanic also told us that he thought that the gear sensors were at fault. However; this was not what was deferred. The Maintenance Supervisor also tried to convince us that the fault had not recurred. His basis for this was that no subsequent write-ups had been made. I tried; unsuccessfully; to explain to him that crews are not required; and rarely do; write up items that already have been deferred and; thus; we have no idea whether or not the fault has recurred. Aircraft refusal as a result of not being able to
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.