Narrative:

Nearing top of descent; got master caution; both IRS 'dc fail' lights illuminated; and the green APU fire bottle light on fire protection panel was dimly pulsing. Read QRH for dc fail. It advises that battery and battery charger may be gone (our situation); but doesn't tell what to expect next. We noted 6 volts on the battery; no amps; and all circuit breaker's in. Maintenance had nothing to recommend when we called them. We continued the JEN8 arrival and landed without incident; but we had quite a few unexpected failures along the way: while navigating on LNAV (autoplt engaged); I noticed that the 'scoreboards' on both sides showed nothing: no modes engaged; nor would they test (however; 'crz' was displayed; at least for a while; as an N1 mode). When the captain disengaged the autoplt; there was no autoplt horn. On rollout; neither thrust reverser deployed; and the #2 annunciation for 'reverser unlocked' illuminated; but the #1 didn't. Taxiing in; we had no master caution indications for several events that should generate them. The aircraft wouldn't accept external power; so we deplaned passenger with the #1 engine running. The APU 'det inoperative' light was illuminated; and by now none of the green fire bottle lights would illuminate on test. Shutting down the #1 engine after all passenger were off; brought the entire aircraft dark; although 'one blue light' was illuminated. The back end did accept ground power (ie ground service bus); which led us to suspect that the problem was related to the lack of any battery or charger; not the power itself. The captain wrote up what happened and gave the logbook and aircraft to maintenance (it was a terminator anyway). Clearly; if other things had gone wrong; we could have been in a far worse situation; since fire protection and emergency exit lights and 'standby power on battery' and the APU generator (by virtue of no ability to start the APU) wouldn't have been available to us. However; we were without much guidance to advise us about all this... We were coming up with an (incomplete!) list of 'what'll we lose' off the tops of our heads during the 'slam dunk' arrival into dal. Given that the battery charger can fail and leave a crew with a drained battery by the time they realize anything is wrong; it seems like the QRH should at least have a list of 'this is what you'll see failing' (IRS on dc is the obvious entry point) and 'this is what you will/won't have available to you' for such a situation. Things like the scoreboard and autoplt horn are pretty minor; but no reverse thrust on landing; and no APU available; might be nice to know about ahead of time! (Also; what else might have been unavailable to us that we didn't know we didn't have???) certainitly; the lack of thrust reverse came as a surprise to us -- not something either of us expected to lose as a result of our situation. I'd suspected ground power might not work; but that was a carryover from a prior aircraft; not anything concrete I can recall from what systems training I've had here. The captain didn't suspect ground power would be unavailable to us. Callback conversation with reporter revealed the following information: the reporter stated several other functions also failed. Autoplt showed no modes engaged; and when autoplt disengaged; there was no autoplt horn. On landing rollout; the thrust reversers failed to deploy. Standby battery power was lost; emergency lighting; fire protection; and the ability to start the auxiliary power unit. Checklist does not tell what is lost in this situation and the reporter suggested the book should be revised. The fix was replacement of the battery charger and battery.

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Original NASA ASRS Text

Title: A B737-500 AT TOP OF DSCNT AT FL350 HAD BOTH DC FAIL LIGHTS ILLUMINATE. RPTR STATES QRH PROCS DID NOT PROVIDE CREW WITH ADEQUATE KNOWLEDGE OF ACFT SYSTEMS AFFECTED.

Narrative: NEARING TOP OF DSCNT; GOT MASTER CAUTION; BOTH IRS 'DC FAIL' LIGHTS ILLUMINATED; AND THE GREEN APU FIRE BOTTLE LIGHT ON FIRE PROTECTION PANEL WAS DIMLY PULSING. READ QRH FOR DC FAIL. IT ADVISES THAT BATTERY AND BATTERY CHARGER MAY BE GONE (OUR SIT); BUT DOESN'T TELL WHAT TO EXPECT NEXT. WE NOTED 6 VOLTS ON THE BATTERY; NO AMPS; AND ALL CB'S IN. MAINT HAD NOTHING TO RECOMMEND WHEN WE CALLED THEM. WE CONTINUED THE JEN8 ARRIVAL AND LANDED WITHOUT INCIDENT; BUT WE HAD QUITE A FEW UNEXPECTED FAILURES ALONG THE WAY: WHILE NAVIGATING ON LNAV (AUTOPLT ENGAGED); I NOTICED THAT THE 'SCOREBOARDS' ON BOTH SIDES SHOWED NOTHING: NO MODES ENGAGED; NOR WOULD THEY TEST (HOWEVER; 'CRZ' WAS DISPLAYED; AT LEAST FOR A WHILE; AS AN N1 MODE). WHEN THE CAPT DISENGAGED THE AUTOPLT; THERE WAS NO AUTOPLT HORN. ON ROLLOUT; NEITHER THRUST REVERSER DEPLOYED; AND THE #2 ANNUNCIATION FOR 'REVERSER UNLOCKED' ILLUMINATED; BUT THE #1 DIDN'T. TAXIING IN; WE HAD NO MASTER CAUTION INDICATIONS FOR SEVERAL EVENTS THAT SHOULD GENERATE THEM. THE ACFT WOULDN'T ACCEPT EXTERNAL POWER; SO WE DEPLANED PAX WITH THE #1 ENG RUNNING. THE APU 'DET INOP' LIGHT WAS ILLUMINATED; AND BY NOW NONE OF THE GREEN FIRE BOTTLE LIGHTS WOULD ILLUMINATE ON TEST. SHUTTING DOWN THE #1 ENG AFTER ALL PAX WERE OFF; BROUGHT THE ENTIRE ACFT DARK; ALTHOUGH 'ONE BLUE LIGHT' WAS ILLUMINATED. THE BACK END DID ACCEPT GND POWER (IE GND SERVICE BUS); WHICH LED US TO SUSPECT THAT THE PROB WAS RELATED TO THE LACK OF ANY BATTERY OR CHARGER; NOT THE POWER ITSELF. THE CAPT WROTE UP WHAT HAPPENED AND GAVE THE LOGBOOK AND ACFT TO MAINT (IT WAS A TERMINATOR ANYWAY). CLEARLY; IF OTHER THINGS HAD GONE WRONG; WE COULD HAVE BEEN IN A FAR WORSE SIT; SINCE FIRE PROTECTION AND EMER EXIT LIGHTS AND 'STANDBY POWER ON BATTERY' AND THE APU GENERATOR (BY VIRTUE OF NO ABILITY TO START THE APU) WOULDN'T HAVE BEEN AVAILABLE TO US. HOWEVER; WE WERE WITHOUT MUCH GUIDANCE TO ADVISE US ABOUT ALL THIS... WE WERE COMING UP WITH AN (INCOMPLETE!) LIST OF 'WHAT'LL WE LOSE' OFF THE TOPS OF OUR HEADS DURING THE 'SLAM DUNK' ARRIVAL INTO DAL. GIVEN THAT THE BATTERY CHARGER CAN FAIL AND LEAVE A CREW WITH A DRAINED BATTERY BY THE TIME THEY REALIZE ANYTHING IS WRONG; IT SEEMS LIKE THE QRH SHOULD AT LEAST HAVE A LIST OF 'THIS IS WHAT YOU'LL SEE FAILING' (IRS ON DC IS THE OBVIOUS ENTRY POINT) AND 'THIS IS WHAT YOU WILL/WON'T HAVE AVAILABLE TO YOU' FOR SUCH A SIT. THINGS LIKE THE SCOREBOARD AND AUTOPLT HORN ARE PRETTY MINOR; BUT NO REVERSE THRUST ON LNDG; AND NO APU AVAILABLE; MIGHT BE NICE TO KNOW ABOUT AHEAD OF TIME! (ALSO; WHAT ELSE MIGHT HAVE BEEN UNAVAILABLE TO US THAT WE DIDN'T KNOW WE DIDN'T HAVE???) CERTAINITLY; THE LACK OF THRUST REVERSE CAME AS A SURPRISE TO US -- NOT SOMETHING EITHER OF US EXPECTED TO LOSE AS A RESULT OF OUR SIT. I'D SUSPECTED GND POWER MIGHT NOT WORK; BUT THAT WAS A CARRYOVER FROM A PRIOR ACFT; NOT ANYTHING CONCRETE I CAN RECALL FROM WHAT SYSTEMS TRAINING I'VE HAD HERE. THE CAPT DIDN'T SUSPECT GND POWER WOULD BE UNAVAILABLE TO US. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED SEVERAL OTHER FUNCTIONS ALSO FAILED. AUTOPLT SHOWED NO MODES ENGAGED; AND WHEN AUTOPLT DISENGAGED; THERE WAS NO AUTOPLT HORN. ON LNDG ROLLOUT; THE THRUST REVERSERS FAILED TO DEPLOY. STANDBY BATTERY POWER WAS LOST; EMER LIGHTING; FIRE PROTECTION; AND THE ABILITY TO START THE AUXILIARY POWER UNIT. CHKLIST DOES NOT TELL WHAT IS LOST IN THIS SIT AND THE RPTR SUGGESTED THE BOOK SHOULD BE REVISED. THE FIX WAS REPLACEMENT OF THE BATTERY CHARGER AND BATTERY.

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.