The United States Federal Aviation Administration has issued an Airworthiness Directive for Boeing 767-200 and 767-300 aircraft, covering bearing failures in the wing flap system.

The failures, "...if not found and fixed, could result in separation of the outboard flap and subsequent loss of control of the airplane."

In December 2000, Boeing issued a Service Bulletin, 767-27A0167, requiring inspection of the bearing, lubrication passages, and replacement of fractured bearings thought due to improper lubrication.

Since then, however, bearing failures have been found in flaps which were properly lubricated and showed no related cause of failure. From this finding, the FAA is issuing the Airworthiness Directive covering all flap bearings on a more frequent inspection and maintenance schedule.

FAA Summary:
"The FAA has received reports indicating that fractured bearings and blocked lubrication passages of the link assembly joint in the inboard and outboard flaps of the trailing edge were found on certain Boeing Model 767 series airplanes. The fractured bearings cause looseness in the joint, resulting in damage to the joint pin, the link assembly bore, and another joint fitting. The bearings were thought to have fractured due to lack of lubrication to the joint, which was caused by shot peen pellets blocking the lubrication passage. However, further data revealed that failure of the bearings can occur even when they are properly lubricated. Such failure in the link assembly joint, if not found and fixed, could result in separation of the outboard flap and consequent loss of control of the airplane."