Incident Overview
On October 9, 2002, Northwest Airlines Flight 85, a scheduled international passenger flight from Detroit Metropolitan Wayne County Airport in the United States to Narita International Airport in Japan, experienced a control system anomaly while over the Bering Sea. The aircraft, a Boeing 747-400, encountered a lower rudder hardover event, a condition in which the rudder deflects to its travel limit without crew input.
Rudder Hardover Event
The hardover resulted in the lower rudder moving to its full left position. In response, the flight crew applied full right upper rudder and full right aileron to maintain the aircraft's attitude and course. The incident occurred during overwater flight, and the crew managed to keep the aircraft under control using available flight controls.
Aftermath
The flight continued to its destination without further reported issues. No specific cause for the hardover was identified in the available information.