A B737-300 experienced total loss of main ship's battery power.

Attributes
ACN	555998
Time
Date	200207
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : zab.artcc
State Reference	NM
Altitude	msl single value : 31000
Environment
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zab.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 15000 flight time type : 12000
ASRS Report	555998
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : dc voltmeter other flight crewa
Resolutory Action	none taken : anomaly accepted other
Consequence	other other Other
Supplementary
Problem Areas	Chart Or Publication Aircraft Flight Crew Human Performance Maintenance Human Performance Company
Primary Problem	Aircraft

Narrative:

After 1.5 hour delay for starter and then start valve change, we had recently leveled off at cruise, when the #1 IRU dc fail light illuminated, followed shortly by the right IRU (inertial reference unit) dc fail. Complied with QRH. Dc system appeared normal. After 1 hour or so the clocks both failed and more checks revealed the battery was down to 6 volts. Maintenance was consulted twice by air phone during this event. After landing several system were inoperative, we had no PA after engine shutdown and the external power was not accepted. We were not particularly concerned because everything except the irc 'dc fail' and clocks were operating normally. Had we remembered that we had no fire protection, only 1 reverser would deploy after landing, the autoplt disengage light and alarm could not be silenced until landing, ground power would not connect to the aircraft and no PA was available or VHF radio after shutdown we'd have been a little better prepared. A note in the QRH to the effect of 'if these lights come on your battery is going dead -- here's a list of what you don't have and won't have after landing' would be useful. Also, I would be expecting a little more expertise and help from maintenance. I am also hoping that the maintenance technician didn't know that we were without fire protection or didn't mention it for concern that we might divert and land short of our destination.

Original NASA ASRS Text

Title: A B737-300 EXPERIENCED TOTAL LOSS OF MAIN SHIP'S BATTERY PWR.

Narrative: AFTER 1.5 HR DELAY FOR STARTER AND THEN START VALVE CHANGE, WE HAD RECENTLY LEVELED OFF AT CRUISE, WHEN THE #1 IRU DC FAIL LIGHT ILLUMINATED, FOLLOWED SHORTLY BY THE R IRU (INERTIAL REF UNIT) DC FAIL. COMPLIED WITH QRH. DC SYS APPEARED NORMAL. AFTER 1 HR OR SO THE CLOCKS BOTH FAILED AND MORE CHKS REVEALED THE BATTERY WAS DOWN TO 6 VOLTS. MAINT WAS CONSULTED TWICE BY AIR PHONE DURING THIS EVENT. AFTER LNDG SEVERAL SYS WERE INOP, WE HAD NO PA AFTER ENG SHUTDOWN AND THE EXTERNAL PWR WAS NOT ACCEPTED. WE WERE NOT PARTICULARLY CONCERNED BECAUSE EVERYTHING EXCEPT THE IRC 'DC FAIL' AND CLOCKS WERE OPERATING NORMALLY. HAD WE REMEMBERED THAT WE HAD NO FIRE PROTECTION, ONLY 1 REVERSER WOULD DEPLOY AFTER LNDG, THE AUTOPLT DISENGAGE LIGHT AND ALARM COULD NOT BE SILENCED UNTIL LNDG, GND PWR WOULD NOT CONNECT TO THE ACFT AND NO PA WAS AVAILABLE OR VHF RADIO AFTER SHUTDOWN WE'D HAVE BEEN A LITTLE BETTER PREPARED. A NOTE IN THE QRH TO THE EFFECT OF 'IF THESE LIGHTS COME ON YOUR BATTERY IS GOING DEAD -- HERE'S A LIST OF WHAT YOU DON'T HAVE AND WON'T HAVE AFTER LNDG' WOULD BE USEFUL. ALSO, I WOULD BE EXPECTING A LITTLE MORE EXPERTISE AND HELP FROM MAINT. I AM ALSO HOPING THAT THE MAINT TECHNICIAN DIDN'T KNOW THAT WE WERE WITHOUT FIRE PROTECTION OR DIDN'T MENTION IT FOR CONCERN THAT WE MIGHT DIVERT AND LAND SHORT OF OUR DEST.

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.