What was found
AIRCRAFT WAS NOT GROUNDED: FLIGHT CREW REPORTED THAT THEY CANNOT OPEN FLIGHT DECK DOOR DURING FLIGHT UNLESS SWITCH MOVED TO LOCK THEN HELD IN UNLOCK POSITION. APPEARS TOP STRIKER IS THE ISSUE. MAINTENANCE FOUND THE UPPER DOOR SIDE LATCH WOULD NOT RETRACT FAR ENOUGH WITH THE DOOR HANDLE TO CLEAR THE UPPER STRIKER ASSEMBLY. MAINTENANCE ADJUSTED THE UPPER DOOR LATCH PER AMM 52-51-00 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF DOOR WITH NO ISSUES NOTED.