Casualties unknown

Banner towing aircraft sustains substantial damage after fuel contamination (N9071D)

Creve Coeur, MO, US

On May 20, 1990, a Piper PA-18A (registration N9071D) was involved in an aviation accident near Creve Coeur, MO. Investigators recorded the probable cause as: The pilot's failure to drain the fuel sumps prior to flight, which resulted in water contamination of the fuel system and subsequent engine power loss. 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 experienced engine power loss during a banner drop operation due to water-contaminated fuel, resulting in a forced landing and substantial aircraft damage.

What happened

The commercial pilot reported that he had just completed a banner drop when he re-entered the downwind leg at approximately 40 feet above ground level. During the turn from downwind to base leg, the pilot switched fuel tanks. Shortly after this action, the aircraft experienced a loss of power. The pilot attempted an emergency landing in a tall wheat field. Upon impact, the aircraft nosed over and sustained substantial damage.

The investigation

A post-accident inspection of the aircraft revealed that the fuel system was contaminated with water. The pilot stated that he had not drained the fuel sumps prior to the flight.

Findings

The investigation determined that water contamination in the fuel system was a primary factor in the engine power loss. Contributing to this failure was the pilot's decision not to drain the fuel sumps before operating the aircraft.

Probable cause

The pilot's failure to drain the fuel sumps prior to flight, which resulted in water contamination of the fuel system and subsequent engine power loss.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23243. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.