As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SDF - FLT 4072 - AFTER TAKEOFF FROM SDF, THE CREW HEARD A VERY LOUD 'EXPLOSION' FROM THE NR 1 ENGINE. THE CAPTAIN THEN SHUT THE ENGINE DOWN. THE CREW DECLARED EMERGENCY AND RETURNED THE AIRCRAFT SAFELY. UPON INITIAL INSPECTION BY CONTRACT MAINTENANCE, IT APPEARS THAT THE BLEED SYSTEM ON THE ENGINE SEPARATED FROM THE ENGINE. REPLACED NR 1 ENGINE ASSY. (M)