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B737-700 captain reported a lack of consensus in applying an MEL to an inoperative boost pump.
| Attributes | |
| ACN | 1696089 |
| Time | |
| Date | 201910 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Dusk |
| Aircraft 1 | |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Fuel Booster Pump |
| Person 1 | |
| Function | Captain Pilot Flying |
| Qualification | Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 312 Flight Crew Type 4000 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural MEL Deviation - Procedural Published Material / Policy Inflight Event / Encounter Fuel Issue |
Narrative:
Enroute to ZZZ; the right center fuel boost pump 'low pressure' light illuminated. I notified both dispatch and maintenance; via ACARS; of the failure. Luckily; the other boost pump operated normally and we were able to burn the center tank fuel to empty the tank and continue normally to ZZZ. Upon landing; ZZZ maintenance consulted maintenance control and elected to defer the pump under MEL 28-X-xx; rather than MEL 28-X-yy. The primary difference between the two mels as I read them; relates to the fuel status of the center tank. 28-X-xx; in my opinion; should be applied when the center tank is empty; as it was in our particular situation. 28-X-yy should have be used when fuel remains in the center tank (as it states in the title of the MEL). I envision this MEL was designed to give relief to an aircraft that has fuel in its center tank; to depart; as long as the fuel; should it become trapped and therefore unusable; does not adversely affect the weight and balance of the aircraft.the other center tank pump is operational in this case and should be able to burn that fuel out of the tank. I do not think that this MEL s intended to give relief to continually fill the center tank; as needed; on subsequent flights; as the failure of the remaining center tank pump would likely cause you to immediately violate the structural limitation in the afm regarding the burning of center tank fuel in excess of 1;000 lbs; prior to using wing tank fuel. If my interpretation of the application of the MEL is incorrect; however; I cannot imagine why MEL 28-X-xx would need to exist. Deferring the item under 28-X-yy would always be operationally preferable. The mere existence of 28-X-xx implies that the goal is to empty the tank if possible and once empty; it should remain so until a repair can be accomplished. I queried maintenance control and was told that they wanted to keep the aircraft able to carry center tank fuel.
Original NASA ASRS Text
Title: B737-700 Captain reported a lack of consensus in applying an MEL to an inoperative boost pump.
Narrative: Enroute to ZZZ; the Right Center Fuel Boost Pump 'Low Pressure' light illuminated. I notified both Dispatch and Maintenance; via ACARS; of the failure. Luckily; the other boost pump operated normally and we were able to burn the center tank fuel to empty the tank and continue normally to ZZZ. Upon landing; ZZZ Maintenance consulted Maintenance Control and elected to defer the pump under MEL 28-X-XX; rather than MEL 28-X-YY. The primary difference between the two MELs as I read them; relates to the fuel status of the center tank. 28-X-XX; in my opinion; should be applied when the center tank is empty; as it was in our particular situation. 28-X-YY should have be used when fuel remains in the center tank (as it states in the title of the MEL). I envision this MEL was designed to give relief to an aircraft that has fuel in its center tank; to depart; as long as the fuel; should it become trapped and therefore unusable; does not adversely affect the weight and balance of the aircraft.The other center tank pump is operational in this case and should be able to burn that fuel out of the tank. I do not think that this MEL s intended to give relief to continually fill the center tank; as needed; on subsequent flights; as the failure of the remaining center tank pump would likely cause you to immediately violate the structural limitation in the AFM regarding the burning of center tank fuel in excess of 1;000 lbs; prior to using wing tank fuel. If my interpretation of the application of the MEL is incorrect; however; I cannot imagine why MEL 28-X-XX would need to exist. Deferring the item under 28-X-YY would always be operationally preferable. The mere existence of 28-X-XX implies that the goal is to empty the tank if possible and once empty; it should remain so until a repair can be accomplished. I queried Maintenance Control and was told that they wanted to keep the aircraft able to carry center tank fuel.
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.