A300 flight crew experienced a dual pack trip climbing out of FL255 which cannot be reset. During de...

Narrative:

Ran normal checklists and departed uneventfully. Climbing out of FL255 both packs tripped. Leveled the aircraft at FL260 and advised ATC. Complied with ECAM and could not restore packs. Checked cabin altitude; which was at 4.5K and climbing at 500 fpm. Noted that pressure on bleed manifold was zero. Since cabin was climbing while level; coordinated descent with ATC and were initially cleared to FL180. At FL180 coordinated with dispatch and maintenance control to inform them of our situation. During coordination; pack number one came back online. Soon later; pack number 2 came online. Solicited input from dispatch and maintenance control. Discussed possible options/solutions. Since we could not determine what caused the packs to trip; we jointly agreed to divert in lieu of continuing over the ocean. Approaching parking; on taxi in; first officer noted APU was on; and questioned whether he had turned it on after landing. This was in part due to having repeatedly turned on the APU immediately after landing all week at destination (they do not hook up ground power) and because of the intensity/time compression typically experienced in such events. First officer advised captain and maintenance of this possibility while reviewing the situation. Although we agreed this was the most likely cause of the pack trips; since neither of us could definitively say whether it was on or not during the flight; maintenance was compelled to investigate. On the ground: maintenance changed engine # 1 and #2 start selector relay. Upon engine start; with all switches verified in the correct position; neither pack would come on line. Shut down aircraft. Maintenance did a full; hard shutdown and restart of the airplane. Second attempt: started engines and packs would not come online. Coordinated on headset with maintenance to accomplish multiple resets of the packs; engine bleeds; and APU bleed. Packs would not come on line. A new part ordered and installed. Next day: flew uneventfully to destination. On climb out for the return flight; noted audible surge from packs. Turned pack 1 off and surge stopped. Continued flight on pack 2. Logbook write up. Recent events at cargo airlines have created a heightened sense of awareness. Given this and rapid development of this situation; we cannot be sure what caused the packs to trip. Further; both the crew and maintenance control were inclined to troubleshoot this problem on the ground rather than in the air; since no obvious cause could be found. It is possible that further in-flight troubleshooting may have revealed the cause one way or the other. Lastly; it is noteworthy that both crew members felt tired on the day in question due to poor sleep for the past the past two nights caused by noise in the hotel. If real-time; in-flight aircraft health and monitoring data is available to maintenance control; including switch positions; in-flight warnings; etc; this data must be included in ground/flight communication to enhance the effectiveness of coordination; especially if that data will hasten a remedy or aid in an emergency.

Original NASA ASRS Text

Title: A300 flight crew experienced a dual pack trip climbing out of FL255 which cannot be reset. During descent; while coordinating with Maintenance; both packs came back on the line. The crew elected to divert and discovers after landing that the APU may have been running in flight.

Narrative: Ran normal checklists and departed uneventfully. Climbing out of FL255 both packs tripped. Leveled the aircraft at FL260 and advised ATC. Complied with ECAM and could not restore packs. Checked cabin altitude; which was at 4.5K and climbing at 500 fpm. Noted that pressure on bleed manifold was zero. Since cabin was climbing while level; coordinated descent with ATC and were initially cleared to FL180. At FL180 coordinated with Dispatch and Maintenance Control to inform them of our situation. During coordination; pack number one came back online. Soon later; pack number 2 came online. Solicited input from Dispatch and Maintenance Control. Discussed possible options/solutions. Since we could not determine what caused the packs to trip; we jointly agreed to divert in lieu of continuing over the ocean. Approaching parking; on taxi in; FO noted APU was on; and questioned whether he had turned it on after landing. This was in part due to having repeatedly turned on the APU immediately after landing all week at destination (they do not hook up ground power) and because of the intensity/time compression typically experienced in such events. FO advised Captain and Maintenance of this possibility while reviewing the situation. Although we agreed this was the most likely cause of the pack trips; since neither of us could definitively say whether it was on or not during the flight; Maintenance was compelled to investigate. ON THE GROUND: Maintenance changed engine # 1 and #2 start selector relay. Upon engine start; with all switches verified in the correct position; neither pack would come on line. Shut down aircraft. Maintenance did a full; hard shutdown and restart of the airplane. Second attempt: Started engines and Packs would not come online. Coordinated on headset with Maintenance to accomplish multiple resets of the packs; engine bleeds; and APU bleed. Packs would not come on line. A new part ordered and installed. Next day: Flew uneventfully to destination. On climb out for the return flight; noted audible surge from packs. Turned pack 1 off and surge stopped. Continued flight on pack 2. Logbook write up. Recent events at cargo airlines have created a heightened sense of awareness. Given this and rapid development of this situation; we cannot be sure what caused the packs to trip. Further; both the crew and Maintenance Control were inclined to troubleshoot this problem on the ground rather than in the air; since no obvious cause could be found. It is possible that further in-flight troubleshooting may have revealed the cause one way or the other. Lastly; it is noteworthy that both crew members felt tired on the day in question due to poor sleep for the past the past two nights caused by noise in the hotel. If real-time; in-flight Aircraft Health and Monitoring Data is available to Maintenance Control; including switch positions; in-flight warnings; etc; this data must be included in ground/flight communication to enhance the effectiveness of coordination; especially if that data will hasten a remedy or aid in an emergency.

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	911075
Time
Date	201009
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	A300
Operating Under FAR Part	Part 121
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 70 Flight Crew Total 15000 Flight Crew Type 2500
Person 2
Function	Pilot Not Flying First Officer
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 6000 Flight Crew Type 1000
Events
Anomaly	Aircraft Equipment Problem Critical

A300 flight crew experienced a dual pack trip climbing out of FL255 which cannot be reset. During descent; while coordinating with maintenance; both packs came back on the line. The crew elected to divert and discovers after landing that the APU may have been running in flight.