Narrative:

Routine transoceanic flight wbound from madrid to atlanta, GA. At 30 degrees west, an electrical malfunction occurred which put red flags into view on most of the captain's instruments, engine instruments, and fail lights in most of the overhead panel. It was not, however, a total electric failure. We all discovered the event at the same time, there was no warning nor any particular chain of events leading up to this point. The disconcerting part of the situation was what we were looking at in the way of red flags, warnings, etc, should not have been happening and was very puzzling. Upon further investigation, we discovered that the bus powering the essential AC bus had failed and that the 'automatic' switching to an alternate source had not occurred, which was the crux of the confusion factor. You know, 'this can't be happening to me,' scenario. After several mins of further investigation and coming to grips with the fact that the essential bus was causing all of our problems (because it was still unpowered), we switched to another source of power manually and things went back to normal for a while! Shortly, the AC essential bus dumped again. We elected to continue status quo, ie, first officer as PF, with good instruments and navigation capabilities until we reached canada, before fooling with any more alternatives. This decision was reached collectively and was, in my opinion, the direct result of our airlines CRM training. We also debated the merits of continuing to final destination versus landing short and again, using CRM skills, arrived at the conclusion that in good flying conditions, with excellent destination WX, there would be no risk. Lessons learned --- don't trust automatic backups and use good CRM skills -- it works.

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Original NASA ASRS Text

Title: L1011-500, AT 30 W LONGITUDE, LOSES PWR TO CAPT'S ESSENTIAL BUS. THE ESSENTIAL AC TRANSFER RELAY FAILS TO SHIFT OVER AND PWR THE CAPT'S BUS, THUS LOSING HIS FLT INSTS, ENG INDICATIONS AND FAIL LIGHTS. CREW ATTEMPTS A CURE AND FINALLY ACCEPTS SIT. THEY CONTINUE THEIR FLT TO DEST ARPT.

Narrative: ROUTINE TRANSOCEANIC FLT WBOUND FROM MADRID TO ATLANTA, GA. AT 30 DEGS W, AN ELECTRICAL MALFUNCTION OCCURRED WHICH PUT RED FLAGS INTO VIEW ON MOST OF THE CAPT'S INSTS, ENG INSTS, AND FAIL LIGHTS IN MOST OF THE OVERHEAD PANEL. IT WAS NOT, HOWEVER, A TOTAL ELECTRIC FAILURE. WE ALL DISCOVERED THE EVENT AT THE SAME TIME, THERE WAS NO WARNING NOR ANY PARTICULAR CHAIN OF EVENTS LEADING UP TO THIS POINT. THE DISCONCERTING PART OF THE SIT WAS WHAT WE WERE LOOKING AT IN THE WAY OF RED FLAGS, WARNINGS, ETC, SHOULD NOT HAVE BEEN HAPPENING AND WAS VERY PUZZLING. UPON FURTHER INVESTIGATION, WE DISCOVERED THAT THE BUS POWERING THE ESSENTIAL AC BUS HAD FAILED AND THAT THE 'AUTOMATIC' SWITCHING TO AN ALTERNATE SOURCE HAD NOT OCCURRED, WHICH WAS THE CRUX OF THE CONFUSION FACTOR. YOU KNOW, 'THIS CAN'T BE HAPPENING TO ME,' SCENARIO. AFTER SEVERAL MINS OF FURTHER INVESTIGATION AND COMING TO GRIPS WITH THE FACT THAT THE ESSENTIAL BUS WAS CAUSING ALL OF OUR PROBS (BECAUSE IT WAS STILL UNPOWERED), WE SWITCHED TO ANOTHER SOURCE OF PWR MANUALLY AND THINGS WENT BACK TO NORMAL FOR A WHILE! SHORTLY, THE AC ESSENTIAL BUS DUMPED AGAIN. WE ELECTED TO CONTINUE STATUS QUO, IE, FO AS PF, WITH GOOD INSTS AND NAV CAPABILITIES UNTIL WE REACHED CANADA, BEFORE FOOLING WITH ANY MORE ALTERNATIVES. THIS DECISION WAS REACHED COLLECTIVELY AND WAS, IN MY OPINION, THE DIRECT RESULT OF OUR AIRLINES CRM TRAINING. WE ALSO DEBATED THE MERITS OF CONTINUING TO FINAL DEST VERSUS LNDG SHORT AND AGAIN, USING CRM SKILLS, ARRIVED AT THE CONCLUSION THAT IN GOOD FLYING CONDITIONS, WITH EXCELLENT DEST WX, THERE WOULD BE NO RISK. LESSONS LEARNED --- DON'T TRUST AUTOMATIC BACKUPS AND USE GOOD CRM SKILLS -- IT WORKS.

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.