Casualties unknown

2000-09-15: Piper PA-31-350 (N4105D) — Emmonak, AK

Emmonak, AK, US

On September 15, 2000, a Piper PA-31-350 (registration N4105D) was involved in an aviation accident near Emmonak, AK. Investigators recorded the probable cause as: The pilot's continued operation of the airplane on unsuitable terrain, and the subsequent failure of the main landing gear torque link. 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

During landing on a rough gravel runway, a twin-engine commuter aircraft's right main landing gear wheel rotated 90 degrees, causing the lower strut and wheel to separate. Metallurgical examination revealed a torque link fracture due to overstress, with no preexisting conditions.

Incident Overview

An airline transport certificated pilot was landing a twin-engine airplane on a rough, gravel runway that contained potholes. The commuter flight had just departed a similar, rough runway. During the landing roll, the airplane rolled down the runway for about 600 feet before the right main landing gear wheel rotated approximately 90 degrees in its landing gear strut housing. The wheel then slid along the surface of the gravel runway for several hundred feet.

Damage and Component Failure

Subsequently, the lower landing gear strut and wheel broke away from the upper strut housing. The right wing settled onto the runway surface. The right propeller tips and the trailing edge of the right flap sustained damage. However, the right wing attach points for the landing gear were not damaged.

Inspection and Metallurgical Findings

Upon inspection of the airplane, a torque link installed on the right main landing gear strut was found fractured at the outer pivot bolt hole. A metallurgical examination of the torque link revealed a fracture through the pivot point of the link with features typical of overstress separation. The examination found no evidence of preexisting conditions, such as crack arrest marks or corrosion damage.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X21899. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.