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.