Casualties unknown

Engine Failure Due to Fuel Contamination During Cruise (N1988P)

Alexander Creek, AK, US

On March 31, 1991, a Piper PA-18-150 (registration N1988P) operated by Charles M. Muschany was involved in an aviation accident near Alexander Creek, AK. Investigators recorded the probable cause as: The pilot's inability to maintain controlled flight following a non-mechanical engine failure caused by fuel system contamination with dirt and debris of undetermined origin. 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 non-mechanical engine failure occurred during cruise flight, leading to a forced landing where the aircraft struck scrub trees and sustained substantial damage.

What happened

The incident occurred while the aircraft was in the cruise phase of flight. The pilot experienced a sudden loss of engine power that was not attributed to mechanical malfunction. Consequently, the pilot initiated a forced landing procedure. The chosen landing area was characterized by the presence of scrub trees. During the descent and touchdown, the airplane collided with these trees, resulting in substantial damage to the airframe.

The investigation

Following the accident, investigators conducted a thorough examination of the aircraft's systems to determine the root cause of the power loss. The inspection focused heavily on the fuel delivery system. Technicians discovered that both the gascolator and the associated fuel lines were contaminated with dirt and debris. The origin of this foreign material could not be determined from the physical evidence. A comprehensive search for other mechanical issues yielded no additional findings, confirming that the engine failure was isolated to the fuel contamination.

Findings

The primary factor leading to the accident was the ingestion of contaminants into the engine's fuel system. The presence of dirt and debris in the gascolator and fuel lines restricted or interrupted fuel flow, causing the non-mechanical engine failure. This loss of power necessitated an emergency landing in unsuitable terrain, which directly resulted in the substantial damage observed upon inspection.

Safety message

Regular maintenance and pre-flight inspections are critical to identifying potential fuel system contaminants. Ensuring that fuel filters, gascolators, and lines are clean and free of debris is essential for preventing in-flight engine failures due to fuel starvation or contamination.

Probable cause

The pilot's inability to maintain controlled flight following a non-mechanical engine failure caused by fuel system contamination with dirt and debris of undetermined origin.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X16536. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.