Casualties unknown

Helicopter Tail Rotor Drive Shaft Fails During Off-Site Landing with Long-Line (C-FBTW)

Cody, WY, US

On August 12, 2001, an Eurocopter AS350 B-2 (registration C-FBTW) was involved in an aviation accident near Cody, WY. Investigators recorded the probable cause as: The long-line became entangled in brush and subsequently in the tail rotor drive shaft, leading to its failure. 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 2026-06-10Data APIEditorial standards

During an off-site landing with a long-line, the line became entangled in brush and then in the tail rotor drive shaft, causing shaft failure. The pilot autorotated, impacting equipment on the ground, resulting in damage to the tail boom, horizontal stabilizer, and fuselage.

Incident Overview

The pilot was performing an off-site landing while operating a helicopter with a long-line attached. During the landing, the long-line became entangled in brush on the ground. Subsequently, the line became entangled around the tail rotor drive shaft.

Sequence of Events

As the line wrapped around the tail rotor drive shaft, the shaft failed. The pilot then performed an autorotation to manage the emergency descent. During the autorotation, the helicopter impacted equipment that was present on the ground.

Damage Assessment

The impact during the landing sequence resulted in structural damage to the helicopter. Specifically, the tail boom and horizontal stabilizer were bent, and the bottom of the helicopter's fuselage was penetrated.

Investigation Findings

The investigation identified that the long-line's entanglement initiated the sequence of events leading to the tail rotor drive shaft failure and subsequent forced landing. No additional causal factors were noted in the source material.

Probable cause

The long-line became entangled in brush and subsequently in the tail rotor drive shaft, leading to its failure.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20010816X01699. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.