On April 18, 1987, a Cessna 170 (registration N1604D) was involved in an aviation accident near Talkeetna, AK. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during takeoff due to a seat track failure that caused the front seat to slide aft. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot lost directional control during takeoff when a front seat adjusting catch disengaged, causing the aircraft to nose over. Investigation revealed worn and distorted seat tracks prevented the adjustment pin from locking.
What happened
During the acceleration phase for takeoff, the adjusting catch for the front seat became disengaged and slid toward the rear of the cabin. This mechanical failure caused the pilot to lose directional control of the aircraft. As a result, the airplane nosed over onto its back.
The investigation
A post-accident examination of the left seat track revealed significant wear and distortion. The damage was severe enough that the adjustment pin could not lock into the full down position, which likely allowed the seat to slide unexpectedly during the high-vibration environment of takeoff.
Probable cause
The pilot's failure to maintain directional control during takeoff due to a seat track failure that caused the front seat to slide aft.