Narrative:

Among many duties of a lead technician at the line maintenance; one is to respond or delegate technicians to respond to any pilot maintenance call; and/or report. At air carrier a maintenance; the technicians are to respond to the commuter pilots' calls as well. Both airlines; I believe; have initiated a minimal training session to maintain air carrier B inflight safety. One morning; air carrier B's maintenance control called our air carrier Z maintenance; requesting to respond to a maintenance issue regarding their aircraft. I responded to the call; and decided to stay overtime; in helping the troubleshooting process to be commenced. The maintenance controller asked me to reset 3 cbs behind the captain's seat. The reset did not resolve the problem; and the APU would not start. Additionally; they had me reset 2 more cbs in the aft accessory compartment; one of which was the circuit breaker for the ecu. Still; the problem was not resolved. The decision was made to MEL the APU. However; the APU external door remained in the open position; and the captain confirmed that. Air carrier B's maintenance control instructed me to reset all cbs; and the captain to attempt in closing the APU's external door by pushing the APU start switch again. This attempt to actuate the door in the closed position failed. Air carrier B's maintenance control then instructed me to manually close the door by turning a 1/4 inch nut clockwise; in an attempt to close the door flush on the fuselage. Air carrier B's maintenance control then would fax the manual reference. At first; I climbed into the aft accessory compartment; where looking aft; I realized that the external door for the APU was further aft; and had to go out; and re-examine the access to the door's actuating mechanism. Further detail observation revealed that I would have had to open the APU cowling to access the door mechanism area. This was the first time I was doing this work. I opened the cowlings; and locked the latches in the position to support the cowlings in the open position. I carefully looked for the 1/4 inch nut; and could not identify it. The actuator motor had a cannon plug attached in at the aft end. At its forward end; the actuator rod was fully extended; and the rod end connected to a lever casting which opened; and closed the APU external door. I disconnected the lever casting at the rod end; and immediately; the door fell in the shut position on its weight. I now understood that the lever casting could be secured to prevent the door from opening. The air carrier B personnel on the ground and the captain; prior to the start of the work; had asked me to give them a board time. I had given them acknowledgement of 1 hour to board time. I felt somewhat I was under time pressure. 2 technicians from air carrier a maintenance had walked out; offering support. No support was needed. I asked one to get the aircraft maintenance manual; air carrier B's maintenance control was to fax. The technician never returned. I proceeded to complete maintenance by double safetying the lever casting with .032 thousandth lock wire; at 2 different places. Then push-pulled on the lever casting to assure tightness; and that the APU's external door would not open; and remain flush to the fuselage. I was convinced that the safety of both lock wires; each going from the same place on the lever-casting; to 2 different areas; were proper. To further assure protection to the actuator assembly; I further safetied the rod end through its bearing (the actuator rod was stuck in full extended position; and could be pushed in); the cannon plug; which I had disconnected at first; was safetied (this would stop the plug from dangling and avoid damage to the wires while aircraft inflight); and also safetied the actuator housing. Convinced with good safety inflight; I shut the APU cowlings; and called the captain to verify the door in the flush position; shut. After captain's clearance; the flight was allowed to board. I proceeded

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Original NASA ASRS Text

Title: A Lead Mechanic describes his involvement with securing an APU inlet door in the closed position; due to an APU that would not start on a CRJ aircraft. Safety wire failed in landing and the APU door opened; allowing the APU to windmill; requiring replacement.

Narrative: Among many duties of a lead technician at the Line Maintenance; one is to respond or delegate technicians to respond to any pilot maintenance call; and/or report. At Air Carrier A maintenance; the technicians are to respond to the Commuter pilots' calls as well. Both airlines; I believe; have initiated a minimal training session to maintain air carrier B inflight safety. One morning; Air Carrier B's Maintenance Control called our Air Carrier Z maintenance; requesting to respond to a maintenance issue regarding their aircraft. I responded to the call; and decided to stay overtime; in helping the troubleshooting process to be commenced. The Maintenance Controller asked me to reset 3 CBs behind the Captain's seat. The reset did not resolve the problem; and the APU would not start. Additionally; they had me reset 2 more CBs in the aft accessory compartment; one of which was the CB for the ECU. Still; the problem was not resolved. The decision was made to MEL the APU. However; the APU external door remained in the open position; and the Captain confirmed that. Air Carrier B's Maintenance Control instructed me to reset all CBs; and the Captain to attempt in closing the APU's external door by pushing the APU start switch again. This attempt to actuate the door in the closed position failed. Air Carrier B's Maintenance Control then instructed me to manually close the door by turning a 1/4 inch nut clockwise; in an attempt to close the door flush on the fuselage. Air Carrier B's Maintenance Control then would fax the manual reference. At first; I climbed into the aft accessory compartment; where looking aft; I realized that the external door for the APU was further aft; and had to go out; and re-examine the access to the door's actuating mechanism. Further detail observation revealed that I would have had to open the APU cowling to access the door mechanism area. This was the first time I was doing this work. I opened the cowlings; and locked the latches in the position to support the cowlings in the open position. I carefully looked for the 1/4 inch nut; and could not identify it. The actuator motor had a cannon plug attached in at the aft end. At its forward end; the actuator rod was fully extended; and the rod end connected to a lever casting which opened; and closed the APU external door. I disconnected the lever casting at the rod end; and immediately; the door fell in the shut position on its weight. I now understood that the lever casting could be secured to prevent the door from opening. The Air Carrier B personnel on the ground and the Captain; prior to the start of the work; had asked me to give them a board time. I had given them acknowledgement of 1 hour to board time. I felt somewhat I was under time pressure. 2 technicians from Air Carrier A maintenance had walked out; offering support. No support was needed. I asked one to get the Aircraft Maintenance Manual; Air Carrier B's maintenance Control was to fax. The Technician never returned. I proceeded to complete maintenance by double safetying the lever casting with .032 thousandth lock wire; at 2 different places. Then push-pulled on the lever casting to assure tightness; and that the APU's external door would not open; and remain flush to the fuselage. I was convinced that the safety of both lock wires; each going from the same place on the lever-casting; to 2 different areas; were proper. To further assure protection to the actuator assembly; I further safetied the rod end through its bearing (the actuator rod was stuck in full extended position; and could be pushed in); the cannon plug; which I had disconnected at first; was safetied (this would stop the plug from dangling and avoid damage to the wires while aircraft inflight); and also safetied the actuator housing. Convinced with good safety inflight; I shut the APU cowlings; and called the Captain to verify the door in the flush position; shut. After Captain's clearance; the flight was allowed to board. I proceeded

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.