AN MD90 CLBING THROUGH 11000 FT DECLARED AN EMER AND DIVERTED DUE TO TOTAL LOSS OF NORMAL AND EMER ELECTRICAL PWR.

Narrative

DEPARTED SNA ON NORMAL PROFILE. AUTOTHROTTLES WERE NOT WORKING; BUT ALL ELSE WAS NORMAL. CAPT'S LEG. TALKING TO SOCAL TRACON AND CLRED TO CLB TO 16000 FT. PASSING THROUGH 11000 FT; WE HAD A TOTAL FAILURE OF ALL ACFT ELECTRICAL SYS EXCEPT BATTERY. THE ELECTRICAL SYS WAS CYCLING BACK ON AND OFF AT A RAPID RATE AND IT SOUNDED LIKE THERE WAS ELECTRICAL ARCING COMING FROM THE CIRCUIT BREAKER PANELS BEHIND CAPT. CAPT'S NIGHT AND IMC HE COULD NOT SEE ANYTHING. AT THIS POINT HE TURNED ACFT OVER TO ME AND TRIED TO DETERMINE IF WE HAD AN ELECTRICAL FIRE. I DECLARED AN EMER AND TURNED THE ACFT TOWARD SNA AND STARTED AN AGGRESSIVE DSCNT TO GET US IN POS AND LAND QUICKLY ON RWY 1 IF THINGS CONTINUED TO GET WORSE. MY ATTITUDE GYRO WAS INTERMITTENT AND I HAD NO HDG. RADIOS WERE COMING AND GOING AND TALKING TO SOCAL WAS ALMOST IMPOSSIBLE. MULTIPLE AURAL WARNINGS WERE GOING OFF AND WE HAD NUMEROUS ANNUNCIATOR LIGHTS/MASTER WARNING MASTER CAUTIONS; ETC. CAPT TRIED TO BOOTSTRAP AND CLOSE DC XTIE BUS. DIDN'T REALLY HELP. SEEMED LIKE AC WAS CYCLING QUICKLY BACK AND FORTH FROM EMER PWR TO R AC. AT THIS POINT WE WERE NEAR THE SHORELINE AND THE IMMEDIATE CONCERN OF A FIRE WAS GONE. NO SMOKE BUT ARCING SOUND PERSISTED. AURAL WARNINGS OF OVERSPD AND ALT ALERT CONTINUED NONSTOP. SINCE NO FIRE DETECTED; I SET UP FOR STABLE APCH TO RWY 19R. VISUAL RECOVERY TO SNA. AUTOSPOILER FAILED AS WE ANTICIPATED. CAPT DEPLOYED SPOILERS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PWR WAS SHIFTING BACK AND FORTH FROM NORMAL PWR TO EMER PWR AT A HIGH FREQ. THE RPTR SAID THE AC PWR RELAYS BEHIND THE CAPT'S SEAT WERE CYCLING AND AT FIRST APPEARED TO BE ARCING BECAUSE OF THE SWITCHING NOISE. THE RPTR SAID THE CAPT'S FLT INSTS (EADI AND EHSI) WERE INOP AND DARK BUT THE FO HAD THE EADI OPERATIVE BUT LOST THE EHSI WHICH WAS DARK. THE RPTR STATED MAINT DID EXTENSIVE WORK ON THE R AC ELECTRICAL SYS AND REPLACED AN INVERTER BUT WAS NOT ADVISED OF THE ACTUAL FAILED COMPONENT.