Narrative:

Flight from sjc to ord (may/xx/96). At FL330 cruise, approximately 1 1/2 hours into the flight, we were approaching cheyenne, wy. We had a master caution light and found it to be the 'APU det inoperative' light. We referred to the irregular procedure in our flight handbook. Paraphrasing, it basically said to not use the APU, or if it was on, turn it off, as we do not have APU fire detection. As per the maintenance book in the aircraft (mrm book) I called aircraft maintenance. They said simply to 'write the problem in the logbook -- we'll get to it in ord.' this was accomplished. Incidentally, the APU had been shut off for approximately 1 1/2 hours -- since pushback at san jose. 15 mins after the master caution, the APU fire warning was triggered. The captain immediately performed the emergency procedure, pulled the fire handle and rotate. The light in the fire handle remained on so we did as instructed -- land at the nearest suitable airport. We could have landed at cys directly below, but both of us were unfamiliar with the field. Was there adequate equipment there for our situation? We did not know. Also, we were at FL330 so the descent would have consumed a lot of time (into cys). The captain had already taken a direct vector to denver after declaring an emergency. A few mins after the emergency, when the situation was under control, I advocated my feeling/choice of landing at the 'nearest' suitable airport (cys). I thought denver was the better choice, but I thought the FAA would choose cys. The captain decided denver as the best choice, and in hindsight, I agree. I was not dead set on cys -- I just wanted to make sure we would consider it as an alternative. CRM was definitely in effect on this flight and made the emergency situation be resolved safely, effectively, and efficiently.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACFT EQUIP PROB. APU FALSE WIRE WARNING. FLC DECLARED EMER AND DIVERTED FLT. B737-300.

Narrative: FLT FROM SJC TO ORD (MAY/XX/96). AT FL330 CRUISE, APPROX 1 1/2 HRS INTO THE FLT, WE WERE APCHING CHEYENNE, WY. WE HAD A MASTER CAUTION LIGHT AND FOUND IT TO BE THE 'APU DET INOP' LIGHT. WE REFERRED TO THE IRREGULAR PROC IN OUR FLT HANDBOOK. PARAPHRASING, IT BASICALLY SAID TO NOT USE THE APU, OR IF IT WAS ON, TURN IT OFF, AS WE DO NOT HAVE APU FIRE DETECTION. AS PER THE MAINT BOOK IN THE ACFT (MRM BOOK) I CALLED ACFT MAINT. THEY SAID SIMPLY TO 'WRITE THE PROB IN THE LOGBOOK -- WE'LL GET TO IT IN ORD.' THIS WAS ACCOMPLISHED. INCIDENTALLY, THE APU HAD BEEN SHUT OFF FOR APPROX 1 1/2 HRS -- SINCE PUSHBACK AT SAN JOSE. 15 MINS AFTER THE MASTER CAUTION, THE APU FIRE WARNING WAS TRIGGERED. THE CAPT IMMEDIATELY PERFORMED THE EMER PROC, PULLED THE FIRE HANDLE AND ROTATE. THE LIGHT IN THE FIRE HANDLE REMAINED ON SO WE DID AS INSTRUCTED -- LAND AT THE NEAREST SUITABLE ARPT. WE COULD HAVE LANDED AT CYS DIRECTLY BELOW, BUT BOTH OF US WERE UNFAMILIAR WITH THE FIELD. WAS THERE ADEQUATE EQUIP THERE FOR OUR SIT? WE DID NOT KNOW. ALSO, WE WERE AT FL330 SO THE DSCNT WOULD HAVE CONSUMED A LOT OF TIME (INTO CYS). THE CAPT HAD ALREADY TAKEN A DIRECT VECTOR TO DENVER AFTER DECLARING AN EMER. A FEW MINS AFTER THE EMER, WHEN THE SIT WAS UNDER CTL, I ADVOCATED MY FEELING/CHOICE OF LNDG AT THE 'NEAREST' SUITABLE ARPT (CYS). I THOUGHT DENVER WAS THE BETTER CHOICE, BUT I THOUGHT THE FAA WOULD CHOOSE CYS. THE CAPT DECIDED DENVER AS THE BEST CHOICE, AND IN HINDSIGHT, I AGREE. I WAS NOT DEAD SET ON CYS -- I JUST WANTED TO MAKE SURE WE WOULD CONSIDER IT AS AN ALTERNATIVE. CRM WAS DEFINITELY IN EFFECT ON THIS FLT AND MADE THE EMER SIT BE RESOLVED SAFELY, EFFECTIVELY, AND EFFICIENTLY.

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.