 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-200 was dispatched with the radio altimeter deferred as inoperative per the MEL ('C' category item 10 day limit) with no mention of the aircraft on the GPWS and TCASII system that are rendered inoperative ('a' category item 2 day limit). A time extension was granted by engineering for 1 day which is in conflict with the MEL requirement.
| Attributes | |
| ACN | 416986 |
| Time | |
| Date | 199810 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz |
| State Reference | US |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | other |
| Flight Plan | None |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | other personnel other oversight : supervisor |
| Qualification | other other : other |
| ASRS Report | 416986 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | other personnel other |
| Qualification | other other : other |
| Events | |
| Anomaly | aircraft equipment problem : critical non adherence : published procedure non adherence : far other anomaly other |
| Independent Detector | other other : unspecified |
| Resolutory Action | none taken : detected after the fact |
| Consequence | Other |
| Supplementary | |
| Air Traffic Incident | other |
Narrative:
The aircraft had a radio altimeter system deferred per the MEL as a 'C' category. The other system affected by this system are GPWS and TCASII. The GPWS is an 'a' category 2-DAY item. The GPWS and TCASII items were not separately deferred. A time extension letter was written to extend it for 1 day to get it to fly 3 flight legs and be rted to ZZZ for repair. If was effectively writing a time-extension letter against an 'a' category item which is not legal. The problem was caused by conflicts in the way the MEL is written. A new revision to correct this is at the FAA waiting for approval.
Original NASA ASRS Text
Title: A B737-200 WAS DISPATCHED WITH THE RADIO ALTIMETER DEFERRED AS INOP PER THE MEL ('C' CATEGORY ITEM 10 DAY LIMIT) WITH NO MENTION OF THE ACFT ON THE GPWS AND TCASII SYS THAT ARE RENDERED INOP ('A' CATEGORY ITEM 2 DAY LIMIT). A TIME EXTENSION WAS GRANTED BY ENGINEERING FOR 1 DAY WHICH IS IN CONFLICT WITH THE MEL REQUIREMENT.
Narrative: THE ACFT HAD A RADIO ALTIMETER SYS DEFERRED PER THE MEL AS A 'C' CATEGORY. THE OTHER SYS AFFECTED BY THIS SYS ARE GPWS AND TCASII. THE GPWS IS AN 'A' CATEGORY 2-DAY ITEM. THE GPWS AND TCASII ITEMS WERE NOT SEPARATELY DEFERRED. A TIME EXTENSION LETTER WAS WRITTEN TO EXTEND IT FOR 1 DAY TO GET IT TO FLY 3 FLT LEGS AND BE RTED TO ZZZ FOR REPAIR. IF WAS EFFECTIVELY WRITING A TIME-EXTENSION LETTER AGAINST AN 'A' CATEGORY ITEM WHICH IS NOT LEGAL. THE PROB WAS CAUSED BY CONFLICTS IN THE WAY THE MEL IS WRITTEN. A NEW REVISION TO CORRECT THIS IS AT THE FAA WAITING FOR APPROVAL.
Data retrieved from NASA's ASRS site as of July 2007 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.