Casualties unknown

Pilot Nosed Over Aircraft While Testing Snow Depth on Mountain Meadow (N4463Z)

Tyonek, AK, US

On October 7, 1995, a Piper PA-18 (registration N4463Z) was involved in an aviation accident near Tyonek, AK. Investigators recorded the probable cause as: The pilot's failure to accurately assess the snow depth prior to landing, which resulted in the airplane nosing over. 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 pilot attempted to land on a snow-covered mountain meadow to test conditions. The aircraft nosed over upon touchdown, revealing deeper snow than estimated.

What happened

The pilot was attempting to land an aircraft on a snow-covered mountain meadow. Prior to the landing attempt, the pilot estimated the depth of the snow to be between 1 and 2 inches. To verify these conditions, he attempted to drag the landing area by lightly touching the main gear on the surface.

When the main gear made contact with the snow, the airplane nosed over. After exiting the aircraft, the pilot observed that the actual depth of the snow was 6 inches and that it was very wet.

The investigation

The examination focused on the discrepancy between the pilot's pre-landing estimation and the actual conditions encountered. The pilot's assessment of 1 to 2 inches proved incorrect, as the true depth was 6 inches. The wet nature of the snow likely contributed to the loss of control during the nose-over event.

Findings

The primary factor in this incident was the inaccurate estimation of snow depth by the pilot. The attempt to drag the landing area did not provide an accurate representation of the surface conditions, leading to the nosing over of the aircraft upon full weight application.

Probable cause

The pilot's failure to accurately assess the snow depth prior to landing, which resulted in the airplane nosing over.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001207X04620. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.