NTSB issues safety recommendations on Boeing 737 rudder system

The National Transportation Safety Board Thursday issued urgent safety recommendations to The Boeing Company (BA) and the Federal Aviation Administration in response to the potential for a jammed or restricted rudder control system on some 737 airplanes. The NTSB is investigating a Feb. 6, 2024, incident in which the rudder pedals on a United Airlines Boeing 737-8, a MAX variant, were “stuck” in their neutral position during the landing rollout at Newark Liberty International Airport, Newark, New Jersey. The captain used the nosewheel steering tiller to control the airplane’s direction after touching down. There was no damage to the airplane or injuries to the 155 passengers and six crewmembers. A preliminary report detailing the circumstances of the event was published on March 12. NTSB investigators tested one of the rudder control components from the incident airplane, a rollout guidance actuator, at the component’s manufacturer, Collins Aerospace (RTX). When the incident actuator and an identical unit from another airplane were tested in a cold environment, the actuators’ function was significantly compromised. nvestigators found evidence of moisture in both actuators, which failed testing. Collins Aerospace subsequently determined that a sealed bearing was incorrectly assembled during production of the actuators, leaving the unsealed side more susceptible to moisture that can freeze and limit rudder system movement. Collins notified Boeing that more than 353 actuators that Collins had delivered to Boeing since February 2017 were affected by this condition. The investigation is ongoing. Additional updates may be issued as circumstances warrant.