Narrative:

Aircraft had a deferred indication on the engine 1 green hydraulic pump and ptu indication. We complied with the ground procedures as outlined in MEL and no ECAM was present at completion of hydraulic pump checks. On climb out going through 1000 ft we got an ECAM G engine 1 lo press as expected. We did not turn the pump off as directed by the ECAM and complied with the MEL direction. The ptu also showed it was operating. A fault light was present in engine 1 green hydraulic pump switch. We continued the climb out. At this point we had no idea if the engine 1 green pump was working or not and I asked maintenance control if there was a way to confirm that the pump was working. He directed us to have the flight attendants check in the cabin and report if they could hear the 'barking dog.' they could not; so the ptu was confirmed to not be operating. My concern with this setup is that after the initial check of the pump; we have no way of knowing when that pump actually fails. The ECAM indication and fault light on the pump switch remained on for the duration of the flight. We asked maintenance control about this and he said we could shut off the ptu to confirm the pump's operation. We did and the pump was working fine. However; the question still remained; how do we know when the pump actually fails if the ECAM already indicates a failure and we're ignoring it per the MEL? Dispatch observed the message traffic and selcaled us to find out if we got the answers we needed. I told her we had not and she suggested getting maintenance control on the SELCAL in a three way conversation. Maintenance control did not want to join in. On arrival I tried to call maintenance control and mr X at ZZZ line maintenance to clear this up; but shift change had just happened and he was not available. Whether it's a 30 minute flight or a 6 hour flight; after the initial pump check; there is no way of knowing if the engine driven hydraulic pump fails on this aircraft.callback conversation with reporter revealed the following information: reporter stated when the #1 engine green hydraulic pump and ptu (power transfer unit) indications are deferred under their MEL for a false 'lo- press' engine hydraulic pump ECAM notice; the flight crew does not have any way of knowing if the engine driven hydraulic pump or ptu may have failed in-flight. The MEL procedure on the ground; after the second engine is started; is to cycle the ptu push button switch from automatic to off and verify on the hydraulic page that the delta symbol for hydraulic pressure is green and the actual numerical pressure indication is 3000 pounds pressure. This indicates the engine hydraulic pump output is normal. But; the engine pump indication will still show a 'lo-pr' failure text. Reporter also stated there are no follow-on procedures in flight to monitor or verify; whether the left engine green hydraulic pump is still functioning; or whether the ptu is actually producing green system hydraulic pressure; or if; in fact; the ptu has failed; when deferring fault indication under the current MEL. The delta symbol and the numerical indication box will continue to show green hydraulic pressure; assuming that either the engine hydraulic pump or the ptu is functioning. Currently; the only way to know that would be to follow the same procedure required when on the ground. But cycling the ptu switch from automatic to off while in-flight cuts out the ptu back-up automatic function and if the engine hydraulic pump has already failed; that would expose the aircraft's entire left green hydraulic system to a system hydraulic pressure loss in-flight. The same scenario could happen if the same MEL were applied to the yellow or right hydraulic system.

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Original NASA ASRS Text

Title: AN AIRBUS A320 PLT RPTS ON THE PROBLEMS WITH A DEFERRED INDICATION ON THE #1 ENG GREEN HYD PUMP AND PTU INDICATION. IN THIS SITUATION THERE IS NO WAY OF KNOWING IF THE ENG DRIVEN HYD PUMP HAS FAILED.

Narrative: ACFT HAD A DEFERRED INDICATION ON THE ENGINE 1 GREEN HYDRAULIC PUMP AND PTU INDICATION. WE COMPLIED WITH THE GND PROCS AS OUTLINED IN MEL AND NO ECAM WAS PRESENT AT COMPLETION OF HYDRAULIC PUMP CHECKS. ON CLBOUT GOING THROUGH 1000 FT WE GOT AN ECAM G ENG 1 LO PRESS AS EXPECTED. WE DID NOT TURN THE PUMP OFF AS DIRECTED BY THE ECAM AND COMPLIED WITH THE MEL DIRECTION. THE PTU ALSO SHOWED IT WAS OPERATING. A FAULT LIGHT WAS PRESENT IN ENG 1 GREEN HYD PUMP SWITCH. WE CONTINUED THE CLBOUT. AT THIS POINT WE HAD NO IDEA IF THE ENG 1 GREEN PUMP WAS WORKING OR NOT AND I ASKED MAINT CTL IF THERE WAS A WAY TO CONFIRM THAT THE PUMP WAS WORKING. HE DIRECTED US TO HAVE THE FLT ATTENDANTS CHECK IN THE CABIN AND RPT IF THEY COULD HEAR THE 'BARKING DOG.' THEY COULD NOT; SO THE PTU WAS CONFIRMED TO NOT BE OPERATING. MY CONCERN WITH THIS SETUP IS THAT AFTER THE INITIAL CHECK OF THE PUMP; WE HAVE NO WAY OF KNOWING WHEN THAT PUMP ACTUALLY FAILS. THE ECAM INDICATION AND FAULT LIGHT ON THE PUMP SWITCH REMAINED ON FOR THE DURATION OF THE FLT. WE ASKED MAINT CTL ABOUT THIS AND HE SAID WE COULD SHUT OFF THE PTU TO CONFIRM THE PUMP'S OPERATION. WE DID AND THE PUMP WAS WORKING FINE. HOWEVER; THE QUESTION STILL REMAINED; HOW DO WE KNOW WHEN THE PUMP ACTUALLY FAILS IF THE ECAM ALREADY INDICATES A FAILURE AND WE'RE IGNORING IT PER THE MEL? DISPATCH OBSERVED THE MESSAGE TFC AND SELCALED US TO FIND OUT IF WE GOT THE ANSWERS WE NEEDED. I TOLD HER WE HAD NOT AND SHE SUGGESTED GETTING MAINT CTL ON THE SELCAL IN A THREE WAY CONVERSATION. MAINT CTL DID NOT WANT TO JOIN IN. ON ARRIVAL I TRIED TO CALL MAINT CTL AND MR X AT ZZZ LINE MAINT TO CLEAR THIS UP; BUT SHIFT CHANGE HAD JUST HAPPENED AND HE WAS NOT AVAILABLE. WHETHER IT'S A 30 MINUTE FLT OR A 6 HOUR FLT; AFTER THE INITIAL PUMP CHK; THERE IS NO WAY OF KNOWING IF THE ENG DRIVEN HYDRAULIC PUMP FAILS ON THIS ACFT.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED WHEN THE #1 ENGINE GREEN HYD PUMP AND PTU (POWER TRANSFER UNIT) INDICATIONS ARE DEFERRED UNDER THEIR MEL FOR A FALSE 'LO- PRESS' ENGINE HYD PUMP ECAM NOTICE; THE FLIGHT CREW DOES NOT HAVE ANY WAY OF KNOWING IF THE ENGINE DRIVEN HYD PUMP OR PTU MAY HAVE FAILED IN-FLIGHT. THE MEL PROCEDURE ON THE GND; AFTER THE SECOND ENGINE IS STARTED; IS TO CYCLE THE PTU PUSH BUTTON SWITCH FROM AUTO TO OFF AND VERIFY ON THE HYD PAGE THAT THE DELTA SYMBOL FOR HYD PRESSURE IS GREEN AND THE ACTUAL NUMERICAL PRESSURE INDICATION IS 3000 LBS PRESSURE. THIS INDICATES THE ENG HYD PUMP OUTPUT IS NORMAL. BUT; THE ENGINE PUMP INDICATION WILL STILL SHOW A 'LO-PR' FAILURE TEXT. RPTR ALSO STATED THERE ARE NO FOLLOW-ON PROCEDURES IN FLIGHT TO MONITOR OR VERIFY; WHETHER THE LEFT ENG GREEN HYD PUMP IS STILL FUNCTIONING; OR WHETHER THE PTU IS ACTUALLY PRODUCING GREEN SYSTEM HYD PRESSURE; OR IF; IN FACT; THE PTU HAS FAILED; WHEN DEFERRING FAULT INDICATION UNDER THE CURRENT MEL. THE DELTA SYMBOL AND THE NUMERICAL INDICATION BOX WILL CONTINUE TO SHOW GREEN HYD PRESSURE; ASSUMING THAT EITHER THE ENG HYD PUMP OR THE PTU IS FUNCTIONING. CURRENTLY; THE ONLY WAY TO KNOW THAT WOULD BE TO FOLLOW THE SAME PROCEDURE REQUIRED WHEN ON THE GND. BUT CYCLING THE PTU SWITCH FROM AUTO TO OFF WHILE IN-FLIGHT CUTS OUT THE PTU BACK-UP AUTO FUNCTION AND IF THE ENG HYD PUMP HAS ALREADY FAILED; THAT WOULD EXPOSE THE ACFT'S ENTIRE LEFT GREEN HYD SYSTEM TO A SYSTEM HYD PRESSURE LOSS IN-FLIGHT. THE SAME SCENARIO COULD HAPPEN IF THE SAME MEL WERE APPLIED TO THE YELLOW OR RIGHT HYD SYSTEM.

Data retrieved from NASA's ASRS site as of May 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.