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A maintenance controller is informed he incorrectly applied an MEL deferral of a #2 VOR/navigation system on a B737-300 that did not have an auxiliary navigation receiver.
| Attributes | |
| ACN | 805633 |
| Time | |
| Date | 200809 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : preflight |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| ASRS Report | 805633 |
| Events | |
| Anomaly | maintenance problem : non compliance with mel maintenance problem : improper documentation non adherence : published procedure non adherence : far |
| Independent Detector | other other : 1 |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other |
| Factors | |
| Maintenance | contributing factor : manuals performance deficiency : non compliance with legal requirements performance deficiency : logbook entry |
| Supplementary | |
| Problem Areas | Aircraft Maintenance Human Performance |
| Primary Problem | Maintenance Human Performance |
Narrative:
Aircraft was loaded and within 10 mins of departure time; when the crew contacted me about a VHF navigation problem; the first officer's VHF navigation control panel was showing all dashes in the frequency window with the manual mode selected. When the panel was selected to automatic mode; the dash marks went away and the local VOR frequency displayed. At the time; I was not aware that the dash marks meant the VOR navigation receiver was in an agility tuning mode -- a common event in-flight when the navigation receiver is searching for the next VOR station. Without properly verifying the aircraft had an auxiliary receiver installed; I deferred the #2 VOR navigation system under MEL 34-17. This was not a legal MEL due to the fact the aircraft does not have an auxiliary receiver installed. The MEL was cleared by maintenance a few days later; which led to my notification that MEL 34-17 was incorrectly applied. To prevent this type of incident from repeating; I have been instructed on how to use the maintenance program to verify the number of navigation receivers installed on the fleet.
Original NASA ASRS Text
Title: A MAINT CONTROLLER IS INFORMED HE INCORRECTLY APPLIED AN MEL DEFERRAL OF A #2 VOR/NAV SYSTEM ON A B737-300 THAT DID NOT HAVE AN AUX NAV RECEIVER.
Narrative: ACFT WAS LOADED AND WITHIN 10 MINS OF DEP TIME; WHEN THE CREW CONTACTED ME ABOUT A VHF NAV PROB; THE FO'S VHF NAV CTL PANEL WAS SHOWING ALL DASHES IN THE FREQ WINDOW WITH THE MANUAL MODE SELECTED. WHEN THE PANEL WAS SELECTED TO AUTO MODE; THE DASH MARKS WENT AWAY AND THE LCL VOR FREQ DISPLAYED. AT THE TIME; I WAS NOT AWARE THAT THE DASH MARKS MEANT THE VOR NAV RECEIVER WAS IN AN AGILITY TUNING MODE -- A COMMON EVENT INFLT WHEN THE NAV RECEIVER IS SEARCHING FOR THE NEXT VOR STATION. WITHOUT PROPERLY VERIFYING THE ACFT HAD AN AUX RECEIVER INSTALLED; I DEFERRED THE #2 VOR NAV SYS UNDER MEL 34-17. THIS WAS NOT A LEGAL MEL DUE TO THE FACT THE ACFT DOES NOT HAVE AN AUX RECEIVER INSTALLED. THE MEL WAS CLRED BY MAINT A FEW DAYS LATER; WHICH LED TO MY NOTIFICATION THAT MEL 34-17 WAS INCORRECTLY APPLIED. TO PREVENT THIS TYPE OF INCIDENT FROM REPEATING; I HAVE BEEN INSTRUCTED ON HOW TO USE THE MAINT PROGRAM TO VERIFY THE NUMBER OF NAV RECEIVERS INSTALLED ON THE FLEET.
Data retrieved from NASA's ASRS site as of May 2009 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.