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|
Attributes | |
ACN | 1356946 |
Time | |
Date | 201605 |
Place | |
Locale Reference | ZZZ.Airport |
State Reference | US |
Aircraft 1 | |
Make Model Name | A319 |
Operating Under FAR Part | Part 121 |
Flight Phase | Parked |
Component | |
Aircraft Component | Air Conditioning and Pressurization Pack |
Person 1 | |
Function | Captain Pilot Not Flying |
Qualification | Flight Crew Air Transport Pilot (ATP) |
Experience | Flight Crew Last 90 Days 90 Flight Crew Total 15000 Flight Crew Type 9000 |
Events | |
Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural FAR Deviation - Procedural MEL Deviation - Procedural Published Material / Policy |
Narrative:
Due to multiple ECAM (electronic centralized aircraft monitoring) notifications prior to takeoff and a return to the gate; the maintenance release in question had two deferrals and associated MEL flight crew procedures that seem incompatible with each other. On this flight pack 2 was deferred inop due to a faulty flow control valve and the no.1 engine hp (high pressure) valve deactivated. Despite independent and numerous cross checks of the pilot procedures to make sure they didn't conflict with each other; another flight crew pointed out an important pressurization issue having these two items deferred at the same time. The pilot procedures for [the MEL] (deactivated hp valve in closed position) state that during flight at low power settings; the associated engine bleed switch should be selected off and the operative bleed pre-cooler outlet temp monitored. If the temp exceeds 240 degrees; the pack associated with the inoperative bleed system should be selected off. If this occurred; the only operative pack would be shut down and a pressurization problem would ensue. Consequently; these two mels are not compatible with each other.
Original NASA ASRS Text
Title: An A319 with conflicting MEL's was issued a Maintenance Release and taxied for takeoff. The crew realized a #1 Pack Flow Control Valve MEL'ed inoperative and a failed #2 Engine High Pressure Bleed Valve could not simultaneously be inoperative. The flight returned to the gate.
Narrative: Due to multiple ECAM (Electronic Centralized Aircraft Monitoring) notifications prior to takeoff and a return to the gate; the maintenance release in question had two deferrals and associated MEL flight crew procedures that seem incompatible with each other. On this Flight Pack 2 was deferred inop due to a faulty flow control valve and the No.1 engine HP (High Pressure) valve deactivated. Despite independent and numerous cross checks of the pilot procedures to make sure they didn't conflict with each other; another flight crew pointed out an important pressurization issue having these two items deferred at the same time. The pilot procedures for [the MEL] (deactivated HP valve in closed position) state that during flight at low power settings; the associated engine bleed switch should be selected off and the operative bleed pre-cooler outlet temp monitored. If the temp exceeds 240 degrees; the pack associated with the inoperative bleed system should be selected off. If this occurred; the only operative pack would be shut down and a pressurization problem would ensue. Consequently; these two MELs are not compatible with each other.
Data retrieved from NASA's ASRS site 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.