Casualties unknown

Engine Roughness Leads to Forced Landing and Collision with Trees (N73533)

Aniak, AK, US

On October 26, 1998, a Cessna 207A (registration N73533) operated by Arctic Circle Air Inc. was involved in an aviation accident near Aniak, AK. Investigators recorded the probable cause as: A loss of engine power due to fuel contamination. A factor in the accident was unsuitable terrain for a forced landing. 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 commercial pilot on an air taxi flight experienced engine roughness after takeoff. Emergency procedures failed, leading to a forced landing in a slough. The aircraft collided with trees, sustaining damage. Fuel contamination was found, but engine testing revealed no mechanical malfunction.

Accident Overview

A certificated commercial pilot and two passengers departed from a remote airport on an air taxi flight. Shortly after takeoff, the pilot climbed the airplane to approximately 1,000 feet mean sea level (msl) when the engine began to run rough. Emergency engine procedures were attempted but did not resolve the roughness.

Sequence of Events

As the airplane began losing altitude, the pilot identified a suitable forced landing area in a slough. During the landing, the airplane collided with trees, resulting in damage to the wings, fuselage, and empennage.

Post-Accident Findings

A sample of fuel taken from the left reservoir tank was observed to be murky and silty, and contained a small amount of water. Laboratory analysis of the fuel sample confirmed that the fuel met the standards for aviation fuel. However, the contamination in the sample consisted of silt and dust, microscopic fibers, and paint chips.

After recovery, examination of the engine did not reveal any mechanical malfunction. Subsequent testing on a test stand demonstrated that the engine produced full power.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X11194. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.