Casualties unknown

Cub aircraft crashes in canyon due to turbulence and terrain strike (N4876A)

Northway, AK, US

On February 27, 1983, a Piper PA-18 (registration N4876A) was involved in an aviation accident near Northway, AK. Investigators recorded the probable cause as: The pilot's failure to maintain terrain clearance during a turn in turbulent conditions within a canyon. 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

A Cub aircraft struck a tree during a turn in Cub Creek canyon after encountering unexpected turbulence, resulting in a stall and crash.

What happened

The pilot was navigating through the narrow confines of Cub Creek when he encountered sudden and unanticipated turbulence. Recognizing the hazardous conditions within the confined space, the pilot decided to execute a 180-degree turn to exit the canyon. During this maneuver, specifically while initiating a left turn, the right wing of the aircraft made contact with a tree.

Following the impact, the aircraft lost lift and stalled. It subsequently crashed into a nearby area characterized by dense brush. Reports indicate that environmental conditions were challenging, with wind gusts reaching speeds of 20 knots contributing to the turbulent environment.

The investigation

The primary mechanical finding centered on the point of initial contact. The right wing struck a tree during the turning maneuver. This impact disrupted the aerodynamic integrity of the aircraft, leading directly to the stall and subsequent crash into the bushy terrain.

Findings

Several factors contributed to the accident sequence. The pilot was operating in a confined canyon environment where space for maneuvering was limited. The presence of unanticipated turbulence within this confined space reduced the margin for error. Additionally, gusting winds up to 20 knots likely exacerbated the turbulence, making the aircraft difficult to control during the critical turn phase. The decision to turn within the canyon, while intended to leave the area, placed the aircraft in proximity to terrain obstacles like trees.

Safety message

Pilots operating in confined spaces such as canyons should remain vigilant for sudden changes in wind patterns and turbulence. Terrain clearance is critical when performing turns in narrow valleys, especially under gusty conditions.

Probable cause

The pilot's failure to maintain terrain clearance during a turn in turbulent conditions within a canyon.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X42113. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.