As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER T/O DURING FLAP RETRACTION A LOUD METAL ON METAL SOUND WAS HEARD THROUGHOUT THE ACFT. THIS NOISE CONFIRMED BY FLT CREW WHILE FLAPS IN MOTION AND CEASED IMMEDIATELY WHEN FLAPS STOPPED. *S/D* INTERNAL FAILURE OF CENTER HYDRAULIC SYSTEM AIR DRIVEN PUMP (ADP) CAUSED GRINDING SOUND IN PUMP. THIS PUMP IS ON DEMAND FOR T/O WITH BOTH LANDING GEAR AND TRAILING EDGE FLAP SYSTEMS OPERATIVE. REPLACED SUBJECT ADP WITH SERVICEABLE UNIT.