Incident Overview
During the final approach phase of landing, a flap vane separated from the right wing of an aircraft. The incident was not immediately noticed by the crew or ground personnel. The aircraft continued its approach and completed an uneventful landing. The separation was only discovered after a local resident contacted authorities to report the fallen part.
Damage
The detached flap vane, measuring 50 inches in length, struck a parked automobile on a street below. The impact caused slight damage to the vehicle. No other property damage or injuries were reported.
Investigation Findings
Investigation into the failure determined that the flap vane separated due to delamination. The delamination resulted from moisture ingestion into the bonded structure. A skin repair had previously been performed on the vane using a cold bond method. The investigation found that inadequate surface preparation and insufficient pressure during the bonding process were major factors contributing to the failure of the bond. The identity of the facility that performed the bond repair was not determined.
Notification
Following the incident, all operators of DC-10 aircraft were notified via telex about the failure and its cause, specifically the delamination of the vane from moisture ingestion.