Narrative:

Upon arrival at the aircraft; I saw that MEL 36-12-01 bleed air supply system was applied on the aircraft. The only crew action is to check placarding procedures. The APU bleed air was MEL'ed because the cover on the respective push button had fallen off. The push button cover was on and had been reattached in some manner. When we started the APU for electrics; we noticed that the APU bleed air came on without us selecting it. This was confirmed by the position of the APU bleed valve position with air pressure indication on both the APU and bleed pages. I attempted turning off the APU bleed air; but the push button felt like it was not engaging. Nothing we did would shut off the APU bleed air. I shut down the APU and called the dispatcher who got maintenance control on the phone. Maintenance control said that the MEL would have to be reclassified and a mechanic came out and applied MEL 36-12-02 APU bleed valve; which requires that maintenance manually secure the bleed valve shut. This was done; however the mechanic stated that the bleed valve may indicate open on the system pages in the cockpit. (I can't remember if his source for this statement was maintenance control or MEL reference materials he had available beyond what is in the cockpit.) we finally started #1 engine using external electrics and an air cart; with plans to do a xbleed start after pushback. Mind you now; temperatures in the cabin are approaching 100 degrees. During the xbleed procedure; we noticed that both the #1 engine intermediate pressure and high pressure bleed valves were closed. We increased power slightly on the #1 engine with no change in bleed air supply. I had felt from the beginning that with the APU bleed valve indicating open that the engine bleeds would not open; and since the cabin temperature was becoming unbearable; I had the ground crew tow us back in to the gate and I instructed the gate agent to immediately deplane the passenger until the maintenance situation was resolved. Several mechanics started the #1 engine and received the same bleed indications we had gotten. They finally decided to change the panel containing the APU bleed air push button and the problem was solved. MEL was removed and we departed about 2 hours late. I recommend that the APU bleed MEL's be reviewed for accuracy regarding actual operation. Even though the APU bleed valve was manually closed; the signal to the valve (assumed to be from the push button) showed the valve open with bleed air being supplied. This then prevented the engine bleeds from opening.

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Original NASA ASRS Text

Title: AN A321 PILOT REPORTS; THAT WHEN STARTING THE APU FOR ELECTRICS; THE APU BLEED AIR CAME ON WITHOUT BEING SELECTED. THIS ALSO CAUSED THE #1 AND #2 ENG IP AND HP BLEED VALVES TO STAY CLOSED AFTER ENG START.

Narrative: UPON ARR AT THE ACFT; I SAW THAT MEL 36-12-01 BLEED AIR SUPPLY SYS WAS APPLIED ON THE ACFT. THE ONLY CREW ACTION IS TO CHK PLACARDING PROCS. THE APU BLEED AIR WAS MEL'ED BECAUSE THE COVER ON THE RESPECTIVE PUSH BUTTON HAD FALLEN OFF. THE PUSH BUTTON COVER WAS ON AND HAD BEEN REATTACHED IN SOME MANNER. WHEN WE STARTED THE APU FOR ELECTRICS; WE NOTICED THAT THE APU BLEED AIR CAME ON WITHOUT US SELECTING IT. THIS WAS CONFIRMED BY THE POS OF THE APU BLEED VALVE POS WITH AIR PRESSURE INDICATION ON BOTH THE APU AND BLEED PAGES. I ATTEMPTED TURNING OFF THE APU BLEED AIR; BUT THE PUSH BUTTON FELT LIKE IT WAS NOT ENGAGING. NOTHING WE DID WOULD SHUT OFF THE APU BLEED AIR. I SHUT DOWN THE APU AND CALLED THE DISPATCHER WHO GOT MAINT CTL ON THE PHONE. MAINT CTL SAID THAT THE MEL WOULD HAVE TO BE RECLASSIFIED AND A MECH CAME OUT AND APPLIED MEL 36-12-02 APU BLEED VALVE; WHICH REQUIRES THAT MAINT MANUALLY SECURE THE BLEED VALVE SHUT. THIS WAS DONE; HOWEVER THE MECH STATED THAT THE BLEED VALVE MAY INDICATE OPEN ON THE SYS PAGES IN THE COCKPIT. (I CAN'T REMEMBER IF HIS SOURCE FOR THIS STATEMENT WAS MAINT CTL OR MEL REF MATERIALS HE HAD AVAILABLE BEYOND WHAT IS IN THE COCKPIT.) WE FINALLY STARTED #1 ENG USING EXTERNAL ELECTRICS AND AN AIR CART; WITH PLANS TO DO A XBLEED START AFTER PUSHBACK. MIND YOU NOW; TEMPS IN THE CABIN ARE APCHING 100 DEGS. DURING THE XBLEED PROC; WE NOTICED THAT BOTH THE #1 ENG INTERMEDIATE PRESSURE AND HIGH PRESSURE BLEED VALVES WERE CLOSED. WE INCREASED PWR SLIGHTLY ON THE #1 ENG WITH NO CHANGE IN BLEED AIR SUPPLY. I HAD FELT FROM THE BEGINNING THAT WITH THE APU BLEED VALVE INDICATING OPEN THAT THE ENG BLEEDS WOULD NOT OPEN; AND SINCE THE CABIN TEMP WAS BECOMING UNBEARABLE; I HAD THE GND CREW TOW US BACK IN TO THE GATE AND I INSTRUCTED THE GATE AGENT TO IMMEDIATELY DEPLANE THE PAX UNTIL THE MAINT SITUATION WAS RESOLVED. SEVERAL MECHS STARTED THE #1 ENG AND RECEIVED THE SAME BLEED INDICATIONS WE HAD GOTTEN. THEY FINALLY DECIDED TO CHANGE THE PANEL CONTAINING THE APU BLEED AIR PUSH BUTTON AND THE PROB WAS SOLVED. MEL WAS REMOVED AND WE DEPARTED ABOUT 2 HRS LATE. I RECOMMEND THAT THE APU BLEED MEL'S BE REVIEWED FOR ACCURACY REGARDING ACTUAL OP. EVEN THOUGH THE APU BLEED VALVE WAS MANUALLY CLOSED; THE SIGNAL TO THE VALVE (ASSUMED TO BE FROM THE PUSH BUTTON) SHOWED THE VALVE OPEN WITH BLEED AIR BEING SUPPLIED. THIS THEN PREVENTED THE ENG BLEEDS FROM OPENING.

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.