Airworthiness Directives; Boeing Model 767 Airplanes

The FAA is superseding an existing airworthiness directive (AD) that applies to all Boeing Model 767 airplanes. That AD currently requires repetitive measurements of the rudder and elevator freeplay, repetitive lubrications of rudder and elevator components, and related investigative/corrective actions if necessary. This new AD instead requires revised repetitive measurements of the rudder freeplay and the elevator freeplay for each of the power control actuators (PCAs) that move the rudder and elevator, corrective and related investigative actions if necessary, and repetitive lubrications of the rudder and elevator components. For some airplanes, this AD also requires related concurrent actions. This 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 issuing this AD to prevent excessive vibration of the airframe during flight, which could result in loss of control of the airplane.