AN MD80 IN CRUISE AT FL350 IN DARKNESS EXPERIENCED LOSS OF L AC BUSS. ALL CABIN LIGHTING AND CABIN INTERPHONE LOST. CAUSED BY L GENERATOR FAILURE.

Narrative

EXPERIENCED A L ENG GENERATOR FAILURE WITH AC X-TIE LOCKOUT LATE AT NIGHT (MD80). ALL OPERATING MANUAL CHKLISTS WERE FOLLOWED AND FULL ELECTRICAL PWR WAS RESTORED IN 3-5 MINS VIA THE APU GENERATOR ON THE L AC BUSS. THE REASON IT TOOK THAT LONG WAS WE WERE CONSTANTLY INTERRUPTED AND DISTR BY 2 OF OUR VERY SENIOR FLT ATTENDANTS POUNDING ON THE COCKPIT DOOR AND SCREAMING AT US. WHEN THE L AC BUS IS UNPWRED; ALL OF THE CABIN LIGHTS GO OUT AND THE CABIN-TO-COCKPIT INTERPHONE IS LOST 'EMER DC BUSS.' NOWHERE IN ANY OF THE CHKLISTS IS THERE A PROC FOR RESTORING INTERPHONE COM WITH AN AC PWR LOSS. WE HAD TO INTERRUPT THE EMER PROCS TO UNBOLT THE DOOR AND TALK TO THE FLT ATTENDANTS SO WE COULD COMPLETE THE PROCS. THE CHKLISTS SHOULD BE UPDATED TO INCLUDE SELECTING EMER PWR FOR A L AC BUSS FAILURE TO RE-ESTABLISH COCKPIT/CABIN COM. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PRIMARY CAUSE OF THE LOSS OF THE L AC BUSS PWR WAS THE L ENG DRIVEN GENERATOR CAME APART. THE RPTR SAID THE CREW WAS UNABLE TO PWR THE L BUSS THROUGH THE X-TIE RELAY WHICH INDICATED BEING LOCKED OUT. THE RPTR STATED THE APU WAS STARTED AND PWRED THE L AC BUSS NORMALLY. THE RPTR SAID WHEN THE L BUSS FAILED THE CABIN LIGHTING AND COCKPIT TO CABIN INTERPHONE FAILED. THE RPTR SAID THE 2 FORWARD CABIN ATTENDANTS BEING ALARMED WERE POUNDING ON THE COCKPIT DOOR AND SCREAMING; INTERFERING WITH THE EMER PROCS. THE RPTR STATED THE EMER PROCS DO NOT COVER RESTORING PWR TO THE INTERPHONE SYS AND SHOULD BE ADDED TO THE CHKLIST. THE RPTR SAID MAINT RPTED ON THE GENERATOR COMING APART; BUT GAVE NO EXPLANATION ON THE X-TIE RELAY FAILING TO CLOSE AND LOCKING OUT.