Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 767 airplanes. This proposed AD would require repetitive measurements of the rudder and elevator freeplay, repetitive lubrication of rudder and elevator components, and related investigative/corrective actions if necessary. This proposed AD results from reports of freeplay-induced vibration of the rudder and the elevator. The potential for vibration of the control surface should be avoided because the point of transition from vibration to divergent flutter is unknown. We are proposing this AD to prevent excessive vibration of the airframe during flight, which could result in loss of control of the airplane.