What was found
ON FINAL APPROACH, FLAPS SELECTED FROM 10 TO 20 DEGREES. AROUND 20 DEGREE MARK, FLAP CIRCUIT BREAKER POPPED. JUST BEFORE TOUCHDOWN PILOT HEARD BANGING SOUND IN CABIN AREA. ACFT LANDED NORMAL. ON INSPECTION, FLAP ACTUATOR MOTOR ASSY FOUND TO BE LOOSE AND BOUNCING UP AND DOWN CAUSING BANGING NOISE. WHEN STRUCTURE REMOVED, IT APPEARED THERE COULD HAVE BEEN AN EXISTING CRACK IN STRUCTURE AS A SLIGHT DISCOLORATION NOTED AROUND A 2 INCH AREA OF THE TORN METAL. AREA LAST INSPECTED ON A PHASE 1, 378 HRS PREVIOUS. NEW PART INSTALLED AFTER A COMPLETE INSPECTION FOR RELATED DAMAGE.