FAA issues safety alert for operators over Boeing 737 rudder issue

The U.S. Federal Aviation Administration issued a safety alert for operations over the potential for a jammed or restricted rudder on Boeing (BA) 737 series aircraft equitted with optional Collins Aerospace (RTX) SVO-730 Rudder Rollout Guidance Actuators. A recent event occurred involving a Boeing 737-8, where the flightcrew was unable to move the rudder pedals during landing rollout. Based on post-incident investigation, it is believed that the Collins Aerospace SVO-730 RRGA was the source of the flight control restriction. The RRGA provides rudder inputs during landing rollout, where directional guidance is provided by the autoflight system after touchdown on CAT IIIB equipped airplanes. The airplane was equipped with the RRGA, but not electrically connected to the Digital Flight Control System. Preliminary findings suggest the jammed or restricted rudder was a result of moisture that had previously entered the actuator and froze during flight. Boeing 737 airplanes with the SVO-730 RRGA installed may be affected by this condition. This also includes airplanes with electrically deactivated actuators that remain mechanically connected to the upper portion of the rudder input torque tube per normal system installation. Airplanes which have the RRGA actuators removed are not affected. Operators should familiarize themselves with the information contained in this SAFO and Boeing’s Multi-Operator Message 24-0142-02B. This MOM references an Operations Manual Bulletin to be provided to each operator to reiterate appropriate flightcrew guidance.