What was found
DURING CRUISE FLIGHT, BOTH PFD'S DISPLAYED ATT/HDG FAILURE ANNUNCIATORS. THESE ANNUNCIATORS WERE FOLLOWED BY TOTAL LOSS OF BOTH PFD'S AND MFD. FAILURES WERE INTERMITTENT FOR SEVERAL MINUTES. (MCC NOTE: PILOT REPORTS FAILURES LASTED SEVERAL SECONDS AND WAS OK ON THE GROUND. CREW REPORTS THAT AC FAIL ANNUNCIATOR ALSO ILLUMINATED; COULD NOT DETERMINE IF COCKPIT WENT TOTALLY BLACK OR NOT (STILL HAD DAYLIGHT AND ATTENTION WAS ON EMERGENCY PROCEDURES); AFTER LANDING AVIONICS POWER SWITCH FELT NORMAL. APPLIED PWR TO AC, POWER UP AVN. NO FAILURES NOTED. GAINED ACCESS TO IC'S CHECKED SECURITY, CHECK GOOD, CHECKED PFD'S AND MFD FOR SECURITY CHECKS- GOOD. GAINED ACCESS TO AC INVERTER IN TAILCONE. FOUND LWR INV CONNECTOR