Incident Overview
A Boeing 727-231, on final approach with landing gear down and locked and flaps at 15 degrees, extended flaps to 30 degrees. The aircraft began to roll right. Controllability was assessed and found satisfactory for continuation of the approach and landing.
Postlanding Findings
After landing, examination of the airplane revealed that the inboard section of the fore flap on the right wing had separated. The separated flap section was located in a street of Howard Beach, New York, approximately 2.5 miles from the approach end of runway 13L.
Metallurgical Examination
Metallurgical examination of the attachment fitting for the inboard fore flap section showed a fatigue crack that originated from grinding marks on the fitting. The source of the grinding marks—whether from the original manufacturer or a rebuilder—was not determined.
Maintenance History
During maintenance, the fitting is inspected visually during a 'C' check, which occurs at 1690-hour intervals. The last C check had taken place 1030 hours before the occurrence.