Narrative:

After all checklists completed as per SOP, flight departed for bwi. After parking the aircraft in bwi, upon shutdown, captain noticed a discrepancy in tail battery voltage (0 volts). Captain contacted maintenance, maintenance repaired the aircraft and advised the flight crew that there was 'no' tail battery in aircraft. Under normal conditions of flight, this would not be noticeable. The battery was installed and the aircraft continued the day with no further incident. With external power connected to the aircraft, the tail battery voltage will read 'system voltage.' it is possible that during the preflight checklists in mdt, this 0 volt discrepancy was unnoticed because the aircraft was pwred externally. The tail battery serves a secondary function on the aircraft, therefore, no noticeable discrepancy, other than '0 volts' indicated on internal power only, would be apparent under normal conditions -- takeoff, cruise and landing. This situation caused no incident and no problems have occurred because of it. Callback conversation with reporter revealed the following: reporter states the function of tail battery is to act as a secondary charge for the igniters. The engines, however, will start without it. Preflight does not include a tail battery check and there is no specific check for battery on acceptance. On internal power there are 3 separate voltage indications but on external power there is only an indication of the total system voltage. This aircraft was on external power. The chief of maintenance said no crew problem would occur as this was completely a maintenance oversight. Some time after the event, the captain was called in for review of the situation and the flight crew became very concerned, that is reason for rather late filing of report. Reporter feels procedure should be established to go to internal power and then check voltage. First officer unable to see gauges from his position.

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Original NASA ASRS Text

Title: LTT FLC FLIES TRIP WITH NO TAIL BATTERY INSTALLED. NOTICES ON SHUTDOWN WHEN VOLTAGE GAUGE GOES TO 0.

Narrative: AFTER ALL CHKLISTS COMPLETED AS PER SOP, FLT DEPARTED FOR BWI. AFTER PARKING THE ACFT IN BWI, UPON SHUTDOWN, CAPT NOTICED A DISCREPANCY IN TAIL BATTERY VOLTAGE (0 VOLTS). CAPT CONTACTED MAINT, MAINT REPAIRED THE ACFT AND ADVISED THE FLC THAT THERE WAS 'NO' TAIL BATTERY IN ACFT. UNDER NORMAL CONDITIONS OF FLT, THIS WOULD NOT BE NOTICEABLE. THE BATTERY WAS INSTALLED AND THE ACFT CONTINUED THE DAY WITH NO FURTHER INCIDENT. WITH EXTERNAL PWR CONNECTED TO THE ACFT, THE TAIL BATTERY VOLTAGE WILL READ 'SYS VOLTAGE.' IT IS POSSIBLE THAT DURING THE PREFLT CHKLISTS IN MDT, THIS 0 VOLT DISCREPANCY WAS UNNOTICED BECAUSE THE ACFT WAS PWRED EXTERNALLY. THE TAIL BATTERY SERVES A SECONDARY FUNCTION ON THE ACFT, THEREFORE, NO NOTICEABLE DISCREPANCY, OTHER THAN '0 VOLTS' INDICATED ON INTERNAL PWR ONLY, WOULD BE APPARENT UNDER NORMAL CONDITIONS -- TKOF, CRUISE AND LNDG. THIS SIT CAUSED NO INCIDENT AND NO PROBS HAVE OCCURRED BECAUSE OF IT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR STATES THE FUNCTION OF TAIL BATTERY IS TO ACT AS A SECONDARY CHARGE FOR THE IGNITERS. THE ENGS, HOWEVER, WILL START WITHOUT IT. PREFLT DOES NOT INCLUDE A TAIL BATTERY CHK AND THERE IS NO SPECIFIC CHK FOR BATTERY ON ACCEPTANCE. ON INTERNAL PWR THERE ARE 3 SEPARATE VOLTAGE INDICATIONS BUT ON EXTERNAL PWR THERE IS ONLY AN INDICATION OF THE TOTAL SYS VOLTAGE. THIS ACFT WAS ON EXTERNAL PWR. THE CHIEF OF MAINT SAID NO CREW PROB WOULD OCCUR AS THIS WAS COMPLETELY A MAINT OVERSIGHT. SOME TIME AFTER THE EVENT, THE CAPT WAS CALLED IN FOR REVIEW OF THE SIT AND THE FLC BECAME VERY CONCERNED, THAT IS REASON FOR RATHER LATE FILING OF RPT. RPTR FEELS PROC SHOULD BE ESTABLISHED TO GO TO INTERNAL PWR AND THEN CHK VOLTAGE. FO UNABLE TO SEE GAUGES FROM HIS POS.

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.