Casualties unknown

1996-04-30: Cessna 170B (N2760D) — Togiak, AK

Togiak, AK, US

On April 30, 1996, a Cessna 170B (registration N2760D) was involved in an aviation accident near Togiak, AK. Investigators recorded the probable cause as: fatigue failure of the right main landing gear strut. 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

A private pilot landed on a gravel beach area; during rollout the right main wheel assembly broke, the strut dragged, and the airplane nosed over. Fatigue marks were found on the strut fracture surfaces.

Incident Overview

A certificated private pilot was performing a landing on a gravel area of a beach adjacent to a river. During the landing roll, the right main wheel assembly failed. The landing gear strut subsequently began dragging along the ground, causing the airplane to nose over.

Examination Findings

Post-incident examination of the landing gear strut revealed that it had fractured along a horizontal plane, perpendicular to the outside vertical surface of the strut. The fracture had propagated through the upper mounting bolt holes that secure the axle and brake mounting plate to the strut. The fractured surface displayed a dark brown/red coloration with ridges or stop marks radiating from the lower inside edge of the aft mounting bolt hole. These stop marks resembled progressive beach marks, which are characteristic of fatigue cracking.

The remaining portion of the fracture surface, located at the inboard edge of the strut between the bolt holes, exhibited a dull gray appearance and a shear lip oriented at approximately a 45-degree angle from the lower surface. Additional fracture surface areas on both the forward and aft sides of the bolt holes were also gray in appearance, with small patches of red rust and corrosion.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001208X05509. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.