Narrative:

I have flown our BK117 with inoperative equipment that possibly was not listed in our MEL. The inoperative equipment is the aft main tank xfer pump. The MEL lists the system and sequence number as 28-2: main tank xfer pump caution lights. Some believe, I am told, that this entry is only referring to the caution lights themselves, not the pump. I disagree and believe they are referring to the pumps. I believe the word 'lights' was listed in this situation because they are the only indication you would have that the pump has failed since there are no fuel pressure gauges. I offer the following explanation as to why I feel this way. Under the remarks or exceptions the first sentence states: 'one may be inoperative provided respective xfer pump is verified operative.' one may be inoperative provided a separate xfer pump is verified operative. 'This can be verified by turning 1 switch on at a time and observing that the caution light is extinguished on operating pump on caution panel.' because each pump has its own segment light, if the second pump failed, you would get a master caution light and a segment light to notify you that you had a failure of the remaining pump. This entry has been read by 3 other pilots and 1 mechanic and all agree that it states you can MEL 1 main fuel xfer pump. If it is determined that this is incorrect and the MEL is only referring to the lights, then everything after the first statement in the remarks or exceptions should be deleted and the word 'respective' should be changed to make it much clrer. You should also include a statement referring to the fact that, if the associated pump fails, you would have no way of knowing and would now have more usable fuel than normal. If it is determined that the pumps are MEL-able then the word 'lights' should be removed from the system and sequence numbers for clarification.

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Original NASA ASRS Text

Title: A EUROCOPTER BK117 B1 PLT BELIEVES THE MEL IS WRONG IN REF TO DEFERRING A MAIN TANK XFER PUMP.

Narrative: I HAVE FLOWN OUR BK117 WITH INOP EQUIP THAT POSSIBLY WAS NOT LISTED IN OUR MEL. THE INOP EQUIP IS THE AFT MAIN TANK XFER PUMP. THE MEL LISTS THE SYS AND SEQUENCE NUMBER AS 28-2: MAIN TANK XFER PUMP CAUTION LIGHTS. SOME BELIEVE, I AM TOLD, THAT THIS ENTRY IS ONLY REFERRING TO THE CAUTION LIGHTS THEMSELVES, NOT THE PUMP. I DISAGREE AND BELIEVE THEY ARE REFERRING TO THE PUMPS. I BELIEVE THE WORD 'LIGHTS' WAS LISTED IN THIS SIT BECAUSE THEY ARE THE ONLY INDICATION YOU WOULD HAVE THAT THE PUMP HAS FAILED SINCE THERE ARE NO FUEL PRESSURE GAUGES. I OFFER THE FOLLOWING EXPLANATION AS TO WHY I FEEL THIS WAY. UNDER THE REMARKS OR EXCEPTIONS THE FIRST SENTENCE STATES: 'ONE MAY BE INOP PROVIDED RESPECTIVE XFER PUMP IS VERIFIED OPERATIVE.' ONE MAY BE INOP PROVIDED A SEPARATE XFER PUMP IS VERIFIED OPERATIVE. 'THIS CAN BE VERIFIED BY TURNING 1 SWITCH ON AT A TIME AND OBSERVING THAT THE CAUTION LIGHT IS EXTINGUISHED ON OPERATING PUMP ON CAUTION PANEL.' BECAUSE EACH PUMP HAS ITS OWN SEGMENT LIGHT, IF THE SECOND PUMP FAILED, YOU WOULD GET A MASTER CAUTION LIGHT AND A SEGMENT LIGHT TO NOTIFY YOU THAT YOU HAD A FAILURE OF THE REMAINING PUMP. THIS ENTRY HAS BEEN READ BY 3 OTHER PLTS AND 1 MECH AND ALL AGREE THAT IT STATES YOU CAN MEL 1 MAIN FUEL XFER PUMP. IF IT IS DETERMINED THAT THIS IS INCORRECT AND THE MEL IS ONLY REFERRING TO THE LIGHTS, THEN EVERYTHING AFTER THE FIRST STATEMENT IN THE REMARKS OR EXCEPTIONS SHOULD BE DELETED AND THE WORD 'RESPECTIVE' SHOULD BE CHANGED TO MAKE IT MUCH CLRER. YOU SHOULD ALSO INCLUDE A STATEMENT REFERRING TO THE FACT THAT, IF THE ASSOCIATED PUMP FAILS, YOU WOULD HAVE NO WAY OF KNOWING AND WOULD NOW HAVE MORE USABLE FUEL THAN NORMAL. IF IT IS DETERMINED THAT THE PUMPS ARE MEL-ABLE THEN THE WORD 'LIGHTS' SHOULD BE REMOVED FROM THE SYS AND SEQUENCE NUMBERS FOR CLARIFICATION.

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.