Casualties unknown

1990-05-28: Stinson 108-1 (N77WC) — Athens, NY

Athens, NY, US

On May 28, 1990, a Stinson 108-1 (registration N77WC) was involved in an aviation accident near Athens, NY. Investigators recorded the probable cause as: The structural failure of the pilot's seat back due to ductile overload at a welded junction, which led to loss of control following takeoff. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

The pilot's seat back fractured just after becoming airborne, causing the aircraft to climb steeply, turn right, stall, and impact inverted with no time for remedial action.

What happened

Shortly after the airplane became airborne, the structural integrity of the pilot's seating assembly failed. The seat back broke, prompting the pilot to tilt backward and pull back on the control wheel in response. This reaction caused the aircraft to climb at a steep angle before turning to the right. The combination of these maneuvers led to an aerodynamic stall, resulting in an inverted impact with the ground. There was insufficient altitude or time for the pilot to execute any remedial action to recover from the situation.

The investigation

A detailed examination of the wreckage focused on the failed seat back assembly. Investigators located the fracture adjacent to a welded junction where the seat back attach point connects to the frame. Metallurgical analysis revealed that the tube frame had failed due to ductile overload. The inspection found no evidence of corrosion or fatigue contributing to the failure, indicating the break was likely caused by immediate excessive stress rather than long-term material degradation.

Findings

The primary factor in this accident was the structural failure of the pilot's seat back immediately after takeoff. This failure disrupted the pilot's ability to maintain normal control inputs, leading directly to the stall and subsequent inverted impact. The mechanical examination confirmed that the frame failed via ductile overload without signs of pre-existing fatigue or corrosion.

Probable cause

The structural failure of the pilot's seat back due to ductile overload at a welded junction, which led to loss of control following takeoff.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23270. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.