Narrative:

Arriving at the airplane, maintenance logbook squawk was (to the best of my memory) 'APU overheat/fire detector inoperative.' the first officer and I analyzed the problem, tested the fault/inoperative and overheat/fire test position and determined that both tests were valid except that overheat/fire test bell was only canceled by depressing fire warning switch on MCP or bell cutout switch on center pedestal for more than 2 seconds. Normal cancellation is a 'momentary' push of either switch. Discussed situation with mechanic. We all agreed that maintenance procedure calling for collaring APU circuit breaker should remain in place, therefore making use of APU impossible.

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Original NASA ASRS Text

Title: A MEDIUM LARGE TRANSPORT LOW WING. DURING PREFLT CHK, CREW QUESTIONS MAINT DEFERRING THE APU AS INOP.

Narrative: ARRIVING AT THE AIRPLANE, MAINT LOGBOOK SQUAWK WAS (TO THE BEST OF MY MEMORY) 'APU OVERHEAT/FIRE DETECTOR INOP.' THE FO AND I ANALYZED THE PROB, TESTED THE FAULT/INOP AND OVERHEAT/FIRE TEST POS AND DETERMINED THAT BOTH TESTS WERE VALID EXCEPT THAT OVERHEAT/FIRE TEST BELL WAS ONLY CANCELED BY DEPRESSING FIRE WARNING SWITCH ON MCP OR BELL CUTOUT SWITCH ON CTR PEDESTAL FOR MORE THAN 2 SECONDS. NORMAL CANCELLATION IS A 'MOMENTARY' PUSH OF EITHER SWITCH. DISCUSSED SIT WITH MECH. WE ALL AGREED THAT MAINT PROC CALLING FOR COLLARING APU CIRCUIT BREAKER SHOULD REMAIN IN PLACE, THEREFORE MAKING USE OF APU IMPOSSIBLE.

Data retrieved from NASA's ASRS site as of July 2007 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.