Casualties unknown

1996-07-12: Cessna 170B (N3156A) — Lewistown, MT

Lewistown, MT, US

On July 12, 1996, a Cessna 170B (registration N3156A) was involved in an aviation accident near Lewistown, MT. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during a landing in gusty crosswind conditions, which resulted in a ground loop. 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 light aircraft sustained substantial damage after a bounce during a crosswind landing caused by sudden wind changes that led to a ground loop.

What happened

The pilot reported conducting an approach to land on the runway under conditions involving a moderate crosswind. As the aircraft descended to approximately three feet above the runway surface, the wind speed decreased significantly or reversed direction entirely. This sudden change in wind conditions caused the airplane to bounce upon contact with the ground. During this bounce, the shifting wind began to turn the aircraft laterally. The pilot was unable to maintain directional control as the airplane turned, resulting in a ground loop that inflicted substantial damage to the airframe.

The investigation

The investigation relied primarily on the pilot's statement regarding the sequence of events during the final approach and landing phase. No mechanical failure or pre-landing anomaly was identified by the pilot prior to the wind shift. The primary factor examined was the interaction between the aircraft's ground handling characteristics and the rapidly changing wind environment.

Findings

The accident was caused by the pilot's inability to maintain directional control during a landing in gusty crosswind conditions. Specifically, the sudden loss or reversal of wind at low altitude led to an uncommanded bounce and subsequent turn that exceeded the pilot's ability to correct. The resulting ground loop placed excessive stress on the landing gear and fuselage, leading to substantial damage.

Safety message

Pilots should be aware that sudden changes in wind speed or direction during the final stages of landing can cause unexpected aircraft behavior. Maintaining adequate control authority and being prepared for rapid corrections is essential when operating in variable wind conditions near the ground.

Probable cause

The pilot's failure to maintain directional control during a landing in gusty crosswind conditions, which resulted in a ground loop.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001208X06370. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.