 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A MD88 was released for flight with an IRU MEL'ed but it was later determined the aircraft was not airworthy because an IRU is not deferrable. The pilots; dispatchers and maintenance did not catch the error.
| Attributes | |
| ACN | 924718 |
| Time | |
| Date | 201012 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | MD-88 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | INS / IRS / IRU |
| Person 1 | |
| Function | First Officer Pilot Not Flying |
| Qualification | Flight Crew Multiengine Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument |
| Experience | Flight Crew Last 90 Days 15 Flight Crew Total 3200 Flight Crew Type 15 |
| Person 2 | |
| Function | Inspector |
| Qualification | Maintenance Powerplant Maintenance Inspection Authority Maintenance Airframe |
| Experience | Maintenance Inspector 1 Maintenance Lead Technician 1 Maintenance Technician 10 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural MEL Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy |
Narrative:
While en route at cruise altitude the command bars on the captain's flight director disappeared while the auto pilot disconnected. The captain hand flew and noticed the #1 IRU flashing 'align'. After two to three minutes; the IRU and flight director returned to normal operation. Auto pilot was re-engaged and a normal arrival was conducted. While parked at the gate the captain placed the #1 IRU to quick align and it would not align in the expected time frame. We had a flight mechanic onboard and advised him. The logbook entry was; '#1 IRU will not align'. He called maintenance control and they came up with deferring the FMS. Prior to pushing back for the return flight the #1 IRU did align and all systems were normal. We were pressed for time for the return flight and as we pushed back; we realized the paperwork was left as is. The return flight was normal. Looking back; the correct log book entry should have been; '#1 IRU intermittent' and the proper corrective action should have been 'ops check normal' and any MEL's should have been removed.
Original NASA ASRS Text
Title: A MD88 was released for flight with an IRU MEL'ed but it was later determined the aircraft was not airworthy because an IRU is not deferrable. The pilots; dispatchers and maintenance did not catch the error.
Narrative: While en route at cruise altitude the command bars on the Captain's flight director disappeared while the auto pilot disconnected. The Captain hand flew and noticed the #1 IRU flashing 'align'. After two to three minutes; the IRU and flight director returned to normal operation. Auto pilot was re-engaged and a normal arrival was conducted. While parked at the gate the Captain placed the #1 IRU to quick align and it would not align in the expected time frame. We had a flight mechanic onboard and advised him. The logbook entry was; '#1 IRU will not align'. He called Maintenance Control and they came up with deferring the FMS. Prior to pushing back for the return flight the #1 IRU did align and all systems were normal. We were pressed for time for the return flight and as we pushed back; we realized the paperwork was left as is. The return flight was normal. Looking back; the correct log book entry should have been; '#1 IRU intermittent' and the proper corrective action should have been 'Ops check normal' and any MEL's should have been removed.
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.