Air carrier medium large transport lost left engine generator at cruise altitude at night. Generator...

Attributes
ACN	80644
Time
Date	198801
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : lbb
State Reference	TX
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 90 flight time total : 10000 flight time type : 11
ASRS Report	80644
Person 2
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time type : 10
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

After leveling the aircraft at FL310 (autoplt engaged), the first officer went aft to the lav. In his absence, the left generator tripped off and an AC power lockout also occurred (rendering the left AC bus isolated). The autoplt kicked off and all instrument lighting also extinguished except for the first officer's instruments. At this point, he re-entered the cockpit and the appropriate checklists were performed. Most flood lighting was regained (except for captain's instruments) and the APU was started. The left AC bus was never regained, thus the following essential equipment was lost: auxiliary hydraulic pump (right system), primary longitudinal (stabilizer) trim, automatic/slat system, automatic spoilers, overhead lights, pedestal lights, center lights, captain's instrument lights, and #1 transponder. An uneventful landing was made back at dfw (point of origin) rather than continue the flight to albuquerque as originally scheduled. Dfw was the closest suitable field. An emergency was not declared and at no time were my altitudes, headings or clrncs not complied with properly. Since this was a night flight, and only the second trip for both pilots (both in new positions and a new aircraft), the potential for a serious situation was certainly present. Some checklist recommendations and manual changes have been forwarded to the company regarding the situation so that improved procedures can be incorporated.

Original NASA ASRS Text

Title: ACR MLG LOST LEFT ENGINE GENERATOR AT CRUISE ALT AT NIGHT. GENERATOR POWER LOCKOUT PREVENTED REACTIVATING LEFT AC BUS. BOTH PLTS WERE NEW TO THEIR RESPECTIVE FLT CREW POSITIONS AND BOTH HAD LOW TIME IN TYPE. RETURN LAND.

Narrative: AFTER LEVELING THE ACFT AT FL310 (AUTOPLT ENGAGED), THE F/O WENT AFT TO THE LAV. IN HIS ABSENCE, THE LEFT GENERATOR TRIPPED OFF AND AN AC PWR LOCKOUT ALSO OCCURRED (RENDERING THE LEFT AC BUS ISOLATED). THE AUTOPLT KICKED OFF AND ALL INSTRUMENT LIGHTING ALSO EXTINGUISHED EXCEPT FOR THE F/O'S INSTRUMENTS. AT THIS POINT, HE RE-ENTERED THE COCKPIT AND THE APPROPRIATE CHKLISTS WERE PERFORMED. MOST FLOOD LIGHTING WAS REGAINED (EXCEPT FOR CAPT'S INSTRUMENTS) AND THE APU WAS STARTED. THE LEFT AC BUS WAS NEVER REGAINED, THUS THE FOLLOWING ESSENTIAL EQUIP WAS LOST: AUX HYD PUMP (RIGHT SYS), PRIMARY LONGITUDINAL (STAB) TRIM, AUTO/SLAT SYS, AUTO SPOILERS, OVERHEAD LIGHTS, PEDESTAL LIGHTS, CENTER LIGHTS, CAPT'S INSTRUMENT LIGHTS, AND #1 TRANSPONDER. AN UNEVENTFUL LNDG WAS MADE BACK AT DFW (POINT OF ORIGIN) RATHER THAN CONTINUE THE FLT TO ALBUQUERQUE AS ORIGINALLY SCHEDULED. DFW WAS THE CLOSEST SUITABLE FIELD. AN EMER WAS NOT DECLARED AND AT NO TIME WERE MY ALTS, HDGS OR CLRNCS NOT COMPLIED WITH PROPERLY. SINCE THIS WAS A NIGHT FLT, AND ONLY THE SECOND TRIP FOR BOTH PLTS (BOTH IN NEW POSITIONS AND A NEW ACFT), THE POTENTIAL FOR A SERIOUS SITUATION WAS CERTAINLY PRESENT. SOME CHKLIST RECOMMENDATIONS AND MANUAL CHANGES HAVE BEEN FORWARDED TO THE COMPANY REGARDING THE SITUATION SO THAT IMPROVED PROCS CAN BE INCORPORATED.

Data retrieved from NASA's ASRS site as of August 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.

Air carrier medium large transport lost left engine generator at cruise altitude at night. Generator power lockout prevented reactivating left AC bus. Both pilots were new to their respective flight crew positions and both had low time in type. Return land.