Regulation & law · 08/09/2006
FAA Issues New Airworthiness Directive for Boeing 747-400 Series Airplanes
The Federal Aviation Administration (FAA) has issued a new airworthiness directive (AD) for Boeing Model 747-400, 747-400D, and 747-400F series airplanes, requiring repetitive inspections of the yaw damper actuator portion of the upper and lower rudder power control modules (PCMs) and replacement if necessary, to prevent cracking that could lead to an uncommanded left rudder hardover and increased pilot workload during landing.