On December 29, 1983, a Boeing 707-123B (registration N2773) operated by American Trans Air, Inc. was involved in an aviation accident near Oakland, CA. Investigators recorded the probable cause as: The nose gear towing and steering connecting link was disconnected from the nose steering collar, with the steering quick release pin installed in the disconnected link, preventing continuity between cockpit steering and the nose wheels, which were allowed… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
The aircraft experienced strong shimmy and vibration during takeoff, attributed to deep snow ruts. After landing, severe vibration forced the pilot to stop on the runway centerline and order evacuation. Investigators found the nose gear steering connecting link was disconnected.
Incident
The aircraft experienced pronounced shimmy and vibration during the initial phase of takeoff. These oscillations were attributed to deep ruts present in the snow on the runway surface. Following landing, as the aircraft decelerated, the vibrations intensified to such a degree that the pilot brought the aircraft to a stop on the runway centerline and directed the occupants to evacuate.
Investigation
An examination of the aircraft after the event revealed that the nose gear towing and steering connecting link had become detached from the nose steering collar. Additionally, the steering quick release pin remained installed in the disconnected link. This condition resulted in a loss of mechanical continuity between the cockpit steering controls and the nose wheels, allowing the nose wheels to move freely without directional control from the pilot.
Probable cause
The nose gear towing and steering connecting link was disconnected from the nose steering collar, with the steering quick release pin installed in the disconnected link, preventing continuity between cockpit steering and the nose wheels, which were allowed free play.
