What was found
(CAN) ON PER FLIGHT PILOT NOTICED LT FLAP WAS NOT FAIRED WITH UPPER WING GAP COVER.FURTHER INSPECTION FOUND L/H INBOARD FLAP MOUNT LOWER BOLT HOLE CRACKED OUT.DUE TO PREVIOUS FAILURES, A FLEET VIAUAL SPECIAL INSPECTION WAS CARRIED OUT, ON INBOARD FLAP MOUNTS, AND REVEALED TWO ADDITIONAL A/C WITH CRACKED MOUNTS. ADDITIONAL NDT INSPECTION WILL BE CARRIED OUT AT OUR 500 HOUR CHECKS. APPROXIMATELY TIME OF UNITS IN SERVICE 2000 HRS. PROBABLE CAUSE A GREATER SPRING (TENSION) LOAD IS USED TO COMPENSATE FOR THE LARGER FLAPS EMPLOYED ON THE METAL SPARED WINGS, AND A HIGHER NUMBER OF FLAP CYCLES PER HOUR USED IN TOWING OPERATION.