Casualties unknown

Engine Failure and Forced Landing After Takeoff Due to Missing Oil Temperature Control Valve (N18SA)

Milwaukee, WI, US

On February 10, 1986, a Cessna 207 (registration N18SA) operated by Burley Harding was involved in an aviation accident near Milwaukee, WI. Investigators recorded the probable cause as: The oil temperature control valve was not installed, and the pilot failed to visually check the oil viscosity after preheating. 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

After preheating, the pilot took off. During climb, smoke filled the cabin and the engine stopped. A forced landing on a city street resulted in the left wing contacting a sign pole.

Incident Summary

After preheating the engine, the pilot took off. During the climb, the cabin filled with smoke and the engine stopped. The pilot performed a forced landing on a city street. During the landing, the left wing contacted a sign pole.

Investigation Findings

A post-accident teardown of the engine revealed that an oil temperature control valve, required to retain engine oil in the crankcase until proper operating temperature is reached, was not installed. Without this temperature valve, oil is permitted to flow through the oil cooler. The pilot also failed to visually check the viscosity of the oil after preheating the engine.

Probable cause

The oil temperature control valve was not installed, and the pilot failed to visually check the oil viscosity after preheating.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X32826. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.