What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS BOTH FLIGHT DIRECTORS BLANK OUT ON TAKEOFF MOMENTARILY, CA RETURNED, FO STAYED BLANK. NO FAULTS NOTED. RIGHT IRS HAD NO POSITION AIRBORNE BUT NO FAULT LIGHT. FO FLIGHT DIRECTOR RETURNED AFTER ENTERING HDG FOR FO. MAINTENANCE REPORTS FFR SHOWS ADIRU(IRU) FAULT #2. MSG 22-11006. ACCOMPLISHED FIM 22-11-00-810-807, ALL CHECKS NORMAL. DFCS BITE CHECK NORMLA. IRU AND FD SYSTEMS CHECK NORMAL.