Narrative:

During the preflight; I reviewed the aml and tried to make sense of the deferred demand C1 hydraulic pump. The defect was C1 demand air driven pump automatic function inoperative. The flight crew action was written as follows: flight crew: a) the following must operate normally: 1) remaining adp (including automatic function). 2) associated adp on and off selector position. B) after engine start: 1) position remaining air demand pump selector to 'on' for all phases of flight. My question for maintenance control was; 'what is the position of the off/automatic/on selector for the associated adp after engine start?' after reading the maintenance actions maintenance control said that the associated pump should be on for all phases of flight. If C1 demand pump should fail then C2 would take over. I pointed out that with both C1 and C2 demand pump switches on; that C2 would be deactivated and never come on. This action also causes the irregular procedure EICAS caution message 'hydraulic pressure dem C2' to be displayed with an icon. The flight crew procedures do not tell us to ignore the caution; override the checklist or complete the checklist; which tells you turn off C2 if the message remains displayed. From my conversation with maintenance control prior to the flight it was clear that both C1 and C2 demand pumps would be on for the entire flight. Prior to flight back to nagoya; I called dispatch from my hotel room and arranged for a conference call. I still was not satisfied with the procedure as written in the release. Going back over all the ground that had been covered the previous day; maintenance control said that the associated demand pump C1 should be on for the entire flight; but then in an additional review of the maintenance procedures stated that there are 3 variations: 1) both automatic functions inoperative (deferrable) 1 pump on the entire flight. 2) 1 automatic function inoperative (deferrable) associated pump on entire flight. 3) 1 adop in (deferrable) remaining adp selector on the entire flight. Interpretation of situation #2 is with 1 adp automatic function inoperative that pump switch will be turned on after engine start and stay on for all phases of flight and the remaining pump is operated normally in the automatic position. Which eliminates the caution message problem; but will C2 actually work in automatic with C1 positioned to on. If the automatic function doesn't work let's say so. The pilot actions for this deferral needs to be written more clearly. My thought is that it is an incorrect procedure the way it is written now.

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Original NASA ASRS Text

Title: CAPT OF B777-200 IS CONFUSED BY DEFERRAL OF AUTO FUNCTION OF THE HYD AIR DEMAND PUMP.

Narrative: DURING THE PREFLT; I REVIEWED THE AML AND TRIED TO MAKE SENSE OF THE DEFERRED DEMAND C1 HYD PUMP. THE DEFECT WAS C1 DEMAND AIR DRIVEN PUMP AUTO FUNCTION INOP. THE FLT CREW ACTION WAS WRITTEN AS FOLLOWS: FLT CREW: A) THE FOLLOWING MUST OPERATE NORMALLY: 1) REMAINING ADP (INCLUDING AUTO FUNCTION). 2) ASSOCIATED ADP ON AND OFF SELECTOR POS. B) AFTER ENG START: 1) POS REMAINING AIR DEMAND PUMP SELECTOR TO 'ON' FOR ALL PHASES OF FLT. MY QUESTION FOR MAINT CTL WAS; 'WHAT IS THE POS OF THE OFF/AUTO/ON SELECTOR FOR THE ASSOCIATED ADP AFTER ENG START?' AFTER READING THE MAINT ACTIONS MAINT CTL SAID THAT THE ASSOCIATED PUMP SHOULD BE ON FOR ALL PHASES OF FLT. IF C1 DEMAND PUMP SHOULD FAIL THEN C2 WOULD TAKE OVER. I POINTED OUT THAT WITH BOTH C1 AND C2 DEMAND PUMP SWITCHES ON; THAT C2 WOULD BE DEACTIVATED AND NEVER COME ON. THIS ACTION ALSO CAUSES THE IRREGULAR PROC EICAS CAUTION MESSAGE 'HYD PRESSURE DEM C2' TO BE DISPLAYED WITH AN ICON. THE FLT CREW PROCS DO NOT TELL US TO IGNORE THE CAUTION; OVERRIDE THE CHKLIST OR COMPLETE THE CHKLIST; WHICH TELLS YOU TURN OFF C2 IF THE MESSAGE REMAINS DISPLAYED. FROM MY CONVERSATION WITH MAINT CTL PRIOR TO THE FLT IT WAS CLR THAT BOTH C1 AND C2 DEMAND PUMPS WOULD BE ON FOR THE ENTIRE FLT. PRIOR TO FLT BACK TO NAGOYA; I CALLED DISPATCH FROM MY HOTEL ROOM AND ARRANGED FOR A CONFERENCE CALL. I STILL WAS NOT SATISFIED WITH THE PROC AS WRITTEN IN THE RELEASE. GOING BACK OVER ALL THE GND THAT HAD BEEN COVERED THE PREVIOUS DAY; MAINT CTL SAID THAT THE ASSOCIATED DEMAND PUMP C1 SHOULD BE ON FOR THE ENTIRE FLT; BUT THEN IN AN ADDITIONAL REVIEW OF THE MAINT PROCS STATED THAT THERE ARE 3 VARIATIONS: 1) BOTH AUTO FUNCTIONS INOP (DEFERRABLE) 1 PUMP ON THE ENTIRE FLT. 2) 1 AUTO FUNCTION INOP (DEFERRABLE) ASSOCIATED PUMP ON ENTIRE FLT. 3) 1 ADOP IN (DEFERRABLE) REMAINING ADP SELECTOR ON THE ENTIRE FLT. INTERP OF SITUATION #2 IS WITH 1 ADP AUTO FUNCTION INOP THAT PUMP SWITCH WILL BE TURNED ON AFTER ENG START AND STAY ON FOR ALL PHASES OF FLT AND THE REMAINING PUMP IS OPERATED NORMALLY IN THE AUTO POS. WHICH ELIMINATES THE CAUTION MESSAGE PROB; BUT WILL C2 ACTUALLY WORK IN AUTO WITH C1 POSITIONED TO ON. IF THE AUTO FUNCTION DOESN'T WORK LET'S SAY SO. THE PLT ACTIONS FOR THIS DEFERRAL NEEDS TO BE WRITTEN MORE CLRLY. MY THOUGHT IS THAT IT IS AN INCORRECT PROC THE WAY IT IS WRITTEN NOW.

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.