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.