As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE NR 1 WAS BEING REMOVED FOR MAINTENANCE. WHEN THE UPPER MOUNT BOLT, WHICH ATTACHES ENGINE TO AIR FRAME WAS BEING REMOVED, THE BOLT STOPPED TURNING AND WAS FROZEN SOLID INTO ENGINE MOUNT. BOLT HEAD WAS CUT OFF TO REMOVE ENGINE. BOLT IS MADE OF STAINLESS STEEL. UPPER MOUNT AND BOLT REQUIRED REPLACEMENT. LOWER MOUNT BOLT WAS REMOVED WITH NO THREAD DAMAGE.