Casualties unknown

1985-08-06: Stinson 108-3 (N4000C) — Montague Island, AK

Montague Island, AK, US

On August 6, 1985, a Stinson 108-3 (registration N4000C) was involved in an aviation accident near Montague Island, AK. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during takeoff due to the left main landing gear sinking in soft sand, which resulted in the aircraft nosing over in incoming tide water. 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 Cessna 172N attempted takeoff from a beach, but the left gear sank into soft sand, pulling the aircraft off course into incoming tide waters.

What happened

The pilot was conducting a takeoff from a beach environment. During the initial roll, the pilot maintained the aircraft close to the waterline to ensure the wheels remained on the firm, hard-packed sand surface. After traveling approximately 700 feet along the runway, the tail wheel was raised as the aircraft rotated for liftoff. At this critical moment, the left main landing gear sank into an area of soft sand. This sudden loss of support pulled the aircraft sharply to the left, causing it to depart the prepared surface. The aircraft then encountered water from an incoming tide and nosed over.

The investigation

The factual narrative indicates that the primary mechanical issue was not a failure of the landing gear itself, but rather the interaction between the tire pressure, the soft sand substrate, and the timing of the tail wheel retraction. The left gear's inability to support the aircraft's weight on the unstable surface led to the directional control loss.

Findings

The accident was caused by the pilot's decision to utilize a beach for takeoff without adequate assessment of the sand conditions and tide levels. The Cessna 172N encountered soft sand which compromised the left main landing gear, leading to a directional deviation into incoming tide water. This resulted in a nose-over incident with no reported injuries to the pilot.

Safety message

Pilots operating from beach environments must carefully evaluate the firmness of the sand surface and be aware of tidal patterns. Taking off from areas that appear firm may be deceptive, as underlying soft layers can cause landing gear sinkage and loss of control during the high-energy phase of takeoff.

Probable cause

The pilot's failure to maintain directional control during takeoff due to the left main landing gear sinking in soft sand, which resulted in the aircraft nosing over in incoming tide water.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X37327. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.