Narrative:

Nov/mon/06; I was the captain assigned to flight. We were assigned an airbus aircraft with 1 bleed inoperative. We were limited to FL310 due to the bleed inoperative. During climb out; the second engine bleed failed. With a tight cabin; the APU was started to control the packs and we leveled off at FL250. The cabin 'delta/dif' was normal with a peak cabin altitude of 5050 ft. Procedures were initiated and appropriate company notifications were made. The purser was briefed as to the situation and what might be expected; and the flight continued towards the destination; 70 mins away. Flight manual limitations were reviewed and 20000 ft was the maximum altitude shown for APU use with 1 pack operation. The situation was evaluated; and the first officer was manning the company communications with maintenance and dispatch. All other system; cabin pressure and parameters were in order. Given our route location; I turned 1 pack off and reduced the flow to low to unload the APU as we were 5000 ft above the APU limitation altitude. APU parameters were below limits and only using 18 psi for duct pressure. Cabin pressure was holding fine. I made the decision to maintain FL250 and did so for several reasons. I wanted to have some working room for any descent over the mountainous areas if the APU or associated bleed failed. There was a terrain issue and I needed to have turning distance to return to and various divert fields. With the APU reduced load and 1 pack; it was performing perfectly. There were no WX issues and various landmark check-points were established as go/no-go decision points. Escape descent paths away from terrain; from these go/no-go locations were determined. Fuel usage was considered an issue and FL250 gave us a little breathing room. Excessive headwinds were present and turbulence was thought to be an issue at lower altitudes. Cost index was used in the headwinds. Cost index used in the light headwinds closer to ZZZ. Method 2 was previously filed for this flight and in play. There were other what-if alternates. I made the decision to remain at FL250 based on all existing flight conditions; situational planning; aircraft and equipment status; terrain; shallow emergency descent planning; crew member capability; diversion potential; discussion with dispatch and maintenance control; and the safe completion of our flight. The flight was completed into ZZZ only 106 seconds late and 100 pounds of fuel ahead of the original flight plan at FL310. Complete passenger comfort and safety was maintained throughout the flight. Aircraft went to the hangar. I write this report; as I made the decision to violate the flight manual limitations of the APU as needed and as stated.

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Original NASA ASRS Text

Title: A B737-300 CAPT WITH BOTH ENG BLEEDS INOP USED THE APU PNEUMATICS AT FL250. CABIN ALT 5000 FT. APU OPERATED ABOVE FLT MANUAL LIMITATIONS.

Narrative: NOV/MON/06; I WAS THE CAPT ASSIGNED TO FLT. WE WERE ASSIGNED AN AIRBUS ACFT WITH 1 BLEED INOP. WE WERE LIMITED TO FL310 DUE TO THE BLEED INOP. DURING CLBOUT; THE SECOND ENG BLEED FAILED. WITH A TIGHT CABIN; THE APU WAS STARTED TO CTL THE PACKS AND WE LEVELED OFF AT FL250. THE CABIN 'DELTA/DIF' WAS NORMAL WITH A PEAK CABIN ALT OF 5050 FT. PROCS WERE INITIATED AND APPROPRIATE COMPANY NOTIFICATIONS WERE MADE. THE PURSER WAS BRIEFED AS TO THE SITUATION AND WHAT MIGHT BE EXPECTED; AND THE FLT CONTINUED TOWARDS THE DEST; 70 MINS AWAY. FLT MANUAL LIMITATIONS WERE REVIEWED AND 20000 FT WAS THE MAX ALT SHOWN FOR APU USE WITH 1 PACK OP. THE SITUATION WAS EVALUATED; AND THE FO WAS MANNING THE COMPANY COMS WITH MAINT AND DISPATCH. ALL OTHER SYS; CABIN PRESSURE AND PARAMETERS WERE IN ORDER. GIVEN OUR RTE LOCATION; I TURNED 1 PACK OFF AND REDUCED THE FLOW TO LOW TO UNLOAD THE APU AS WE WERE 5000 FT ABOVE THE APU LIMITATION ALT. APU PARAMETERS WERE BELOW LIMITS AND ONLY USING 18 PSI FOR DUCT PRESSURE. CABIN PRESSURE WAS HOLDING FINE. I MADE THE DECISION TO MAINTAIN FL250 AND DID SO FOR SEVERAL REASONS. I WANTED TO HAVE SOME WORKING ROOM FOR ANY DSCNT OVER THE MOUNTAINOUS AREAS IF THE APU OR ASSOCIATED BLEED FAILED. THERE WAS A TERRAIN ISSUE AND I NEEDED TO HAVE TURNING DISTANCE TO RETURN TO AND VARIOUS DIVERT FIELDS. WITH THE APU REDUCED LOAD AND 1 PACK; IT WAS PERFORMING PERFECTLY. THERE WERE NO WX ISSUES AND VARIOUS LANDMARK CHK-POINTS WERE ESTABLISHED AS GO/NO-GO DECISION POINTS. ESCAPE DSCNT PATHS AWAY FROM TERRAIN; FROM THESE GO/NO-GO LOCATIONS WERE DETERMINED. FUEL USAGE WAS CONSIDERED AN ISSUE AND FL250 GAVE US A LITTLE BREATHING ROOM. EXCESSIVE HEADWINDS WERE PRESENT AND TURB WAS THOUGHT TO BE AN ISSUE AT LOWER ALTS. COST INDEX WAS USED IN THE HEADWINDS. COST INDEX USED IN THE LIGHT HEADWINDS CLOSER TO ZZZ. METHOD 2 WAS PREVIOUSLY FILED FOR THIS FLT AND IN PLAY. THERE WERE OTHER WHAT-IF ALTERNATES. I MADE THE DECISION TO REMAIN AT FL250 BASED ON ALL EXISTING FLT CONDITIONS; SITUATIONAL PLANNING; ACFT AND EQUIP STATUS; TERRAIN; SHALLOW EMER DSCNT PLANNING; CREW MEMBER CAPABILITY; DIVERSION POTENTIAL; DISCUSSION WITH DISPATCH AND MAINT CTL; AND THE SAFE COMPLETION OF OUR FLT. THE FLT WAS COMPLETED INTO ZZZ ONLY 106 SECONDS LATE AND 100 LBS OF FUEL AHEAD OF THE ORIGINAL FLT PLAN AT FL310. COMPLETE PAX COMFORT AND SAFETY WAS MAINTAINED THROUGHOUT THE FLT. ACFT WENT TO THE HANGAR. I WRITE THIS RPT; AS I MADE THE DECISION TO VIOLATE THE FLT MANUAL LIMITATIONS OF THE APU AS NEEDED AND AS STATED.

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.