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The B737-300 MEL procedure for deferring a thrust reverser requires circuit breakers to be pulled and locked. All breakers labeled per engine except control and indication on P6-2 panel.
| Attributes | |
| ACN | 692412 |
| Time | |
| Date | 200604 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : san.airport |
| State Reference | CA |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : zzz.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : parked |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Experience | flight time last 90 days : 200 flight time total : 10000 flight time type : 5000 |
| ASRS Report | 692412 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | oversight : coordinator |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : non compliance with mel non adherence : far non adherence : published procedure |
| Independent Detector | other flight crewa other flight crewb |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other |
| Supplementary | |
| Problem Areas | Aircraft Chart Or Publication Flight Crew Human Performance Maintenance Human Performance |
| Primary Problem | Aircraft |
| Situations | |
| Publication | MEL |
Narrative:
Reference engine #1 thrust reverser inoperative. MEL. The procedure requires sync lock; thrust reverser control and indication circuit breakers to be pulled. Engine sync lock circuit breaker is labeled indicating which engine #1 or #2; but cont and ind circuit breakers are not labeled which engine they belong to on the P6-2 panel. If the incorrect circuit breaker was inadvertently pulled; both reversers wouldn't work. After talking with line maintenance we both felt the MEL card should be more descriptive and the P6-2 panel should be placarded to indicate which engine is associated with the cont and ind circuit breakers. I also just talked to maintenance headquarters and he also said this deferral is confusing. Just something to consider from a safety perspective.
Original NASA ASRS Text
Title: THE B737-300 MEL PROC FOR DEFERRING A THRUST REVERSER REQUIRES CIRCUIT BREAKERS TO BE PULLED AND LOCKED. ALL BREAKERS LABELED PER ENG EXCEPT CTL AND INDICATION ON P6-2 PANEL.
Narrative: REF ENG #1 THRUST REVERSER INOP. MEL. THE PROC REQUIRES SYNC LOCK; THRUST REVERSER CONTROL AND INDICATION CIRCUIT BREAKERS TO BE PULLED. ENG SYNC LOCK CIRCUIT BREAKER IS LABELED INDICATING WHICH ENG #1 OR #2; BUT CONT AND IND CIRCUIT BREAKERS ARE NOT LABELED WHICH ENG THEY BELONG TO ON THE P6-2 PANEL. IF THE INCORRECT CIRCUIT BREAKER WAS INADVERTENTLY PULLED; BOTH REVERSERS WOULDN'T WORK. AFTER TALKING WITH LINE MAINT WE BOTH FELT THE MEL CARD SHOULD BE MORE DESCRIPTIVE AND THE P6-2 PANEL SHOULD BE PLACARDED TO INDICATE WHICH ENG IS ASSOCIATED WITH THE CONT AND IND CIRCUIT BREAKERS. I ALSO JUST TALKED TO MAINT HEADQUARTERS AND HE ALSO SAID THIS DEFERRAL IS CONFUSING. JUST SOMETHING TO CONSIDER FROM A SAFETY PERSPECTIVE.
Data retrieved from NASA's ASRS site as of January 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.