Casualties unknown

Uncertified Pilot Crashes Plane into Tree Near Frozen Lake (N7121P)

Port Alsworth, AK, US

On December 23, 1993, a Piper PA-18 (registration N7121P) operated by Alsworth, John H. was involved in an aviation accident near Port Alsworth, AK. Investigators recorded the probable cause as: The pilot's decision to operate an aircraft without a valid medical certificate, which had been denied due to his daily use of anti-seizure medication. 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 without a valid medical certificate crashed an aircraft into a tree while approaching a frozen lake in August 1971, having been denied certification due to daily anti-seizure medication use.

What happened

The accident occurred during the final approach phase of flight toward an ice-frozen lake. The aircraft collided with a tree during this maneuver. The individual operating the aircraft was not holding a valid pilot certificate at the time of the incident.

The investigation

Records from the Federal Air Surgeon indicate that the pilot's application for a medical certificate was denied in August 1971. The denial was based on the pilot's medical history, specifically regarding medication usage. The pilot stated that he had been taking anti-seizure medication daily for the preceding twenty years without experiencing any recurring health problems or adverse effects.

Findings

The primary factor contributing to this accident was the operation of an aircraft by a person who did not hold a valid pilot certificate. This status was directly linked to the denial of his medical certification due to his long-term use of anti-seizure medication.

Probable cause

The pilot's decision to operate an aircraft without a valid medical certificate, which had been denied due to his daily use of anti-seizure medication.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X13815. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.