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|
Attributes | |
ACN | 1234755 |
Time | |
Date | 201501 |
Place | |
Locale Reference | ZZZZ.Airport |
State Reference | FO |
Aircraft 1 | |
Make Model Name | A320 |
Operating Under FAR Part | Part 121 |
Flight Phase | Parked Taxi |
Component | |
Aircraft Component | Autoflight System |
Person 1 | |
Function | Other / Unknown |
Qualification | Maintenance Airframe Maintenance Powerplant |
Events | |
Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy |
Narrative:
An A320 aircraft arrived to airport ZZZ with a log item for FMGC-1 inoperative. An attempt to reset the computer per trouble shooting manual (tsm) 24-00-00-810 was not successful. At this point MEL 22-83-Y was complied with; for the FMGC-1 inoperative. The circuit breaker was pulled and autoland status downgrade placard installed. Per MEL instruction MEL 34-48-east was also applied for the terrain avoidance and warning system (taws) inoperative. The aircraft pushed off the blocks for its next flight leg; but returned to the blocks when dispatch advised that they could not dispatch the aircraft due to weather minimums. At this time; another circuit breaker cycle was attempted and was successful. The applicable aircraft maintenance manual (amm) test was completed auto flight system (afs) test 22-96-00 and all systems passed. The MEL 22-83-Y and 34-48-east procedures were reversed and the aircraft returned to normal configuration. The autoland status downgrade placard was also removed. A new maintenance release was completed and sent to the flight deck. The question has been raised as to the validity of the autoland status and if the land verify test needed to be completed. At the time of the incident I did not feel the land verify test was applicable for the following reasons:1) general maintenance manual (gmm) 05-35-40 states if a CAT ii/III component of system is reported to be malfunctioning; it will require that the system test specified in the applicable amm-fim fault isolation manual be accomplished. If a CAT ii/III component; listed in the CAT component tables is replaced; reseated; swapped or associated wiring; plug or receptacle is disconnected; the ground recertification procedure must also be accomplished by a CAT ii/III qualified technician before retaining or upgrading the CAT status. Note: cycling of circuit breakers does not require ground recertification. 2) MEL general - definitions: takeoff: ...for purposes of MEL relief; this translates to the point at which the pilot physically begins to apply power to initiate the takeoff...all actions that were taken were within the applicable amm; tsm and MEL requirements before the aircraft reached the point of dispatch. No system components were disturbed. The flight was never at the point of dispatch - movement of the throttles for takeoff. I do understand that if the aircraft indeed proceeded through the point of dispatch or actually flew; then a CAT recertification would have been necessary. As an additional note; there are systems that affect the CAT status of the aircraft; requiring CAT downgrade placards being installed; that when repaired do not require a CAT recertification; only that the placard be removed. Ref MEL 24-03-0 for engine driven generator channel.if my interpretations of this are incorrect; then I believe a more clearly defined policy should be implemented such as: before removing any autoland downgrade placard; a ground recertification must be accomplished.
Original NASA ASRS Text
Title: A Maintenance Controller explains why he believes an A320 'Land Verify Test' was not required for an FMGC-1 that had been MEL'd under Chapter 22-83-00; but later reversed prior to dispatch; when another Circuit Breaker (C/B) cycle attempt was successful.
Narrative: An A320 aircraft arrived to Airport ZZZ with a log item for FMGC-1 INOP. An attempt to reset the computer per Trouble Shooting Manual (TSM) 24-00-00-810 was not successful. At this point MEL 22-83-Y was complied with; for the FMGC-1 INOP. The CB was pulled and Autoland Status downgrade placard installed. Per MEL instruction MEL 34-48-E was also applied for the Terrain Avoidance and Warning System (TAWS) INOP. The aircraft pushed off the blocks for its next flight leg; but returned to the blocks when Dispatch advised that they could not dispatch the aircraft due to weather minimums. At this time; another CB cycle was attempted and was successful. The applicable Aircraft Maintenance Manual (AMM) test was completed Auto Flight System (AFS) Test 22-96-00 and all systems passed. The MEL 22-83-Y and 34-48-E procedures were reversed and the aircraft returned to normal configuration. The Autoland Status downgrade placard was also removed. A new Maintenance Release was completed and sent to the flight deck. The question has been raised as to the validity of the Autoland Status and if the Land Verify Test needed to be completed. At the time of the incident I did not feel the Land Verify Test was applicable for the following reasons:1) General Maintenance Manual (GMM) 05-35-40 states if a CAT II/III component of system is reported to be malfunctioning; it will require that the system test specified in the applicable AMM-FIM Fault Isolation Manual be accomplished. If a CAT II/III component; listed in the CAT component tables is replaced; reseated; swapped or associated wiring; plug or receptacle is disconnected; the Ground Recertification procedure must also be accomplished by a CAT II/III Qualified Technician before retaining or upgrading the CAT Status. NOTE: Cycling of circuit breakers does not require Ground recertification. 2) MEL General - Definitions: Takeoff: ...For purposes of MEL relief; this translates to the point at which the pilot physically begins to apply power to initiate the takeoff...All actions that were taken were within the applicable AMM; TSM and MEL requirements before the aircraft reached the point of dispatch. No system components were disturbed. The flight was never at the point of dispatch - movement of the throttles for takeoff. I do understand that if the aircraft indeed proceeded through the point of dispatch or actually flew; then a CAT recertification would have been necessary. As an additional note; there are systems that affect the CAT status of the aircraft; requiring CAT Downgrade placards being installed; that when repaired do not require a CAT recertification; only that the placard be removed. Ref MEL 24-03-0 for Engine Driven Generator Channel.If my interpretations of this are incorrect; then I believe a more clearly defined policy should be implemented such as: Before removing any Autoland Downgrade Placard; a Ground recertification must be accomplished.
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.