Casualties unknown

Engine Power Loss Leads to Forced Landing and Inverted Rest (N7733R)

Knoxville, TN, US

On August 27, 1993, a Beech V35A (registration N7733R) was involved in an aviation accident near Knoxville, TN. Investigators recorded the probable cause as: Corrosive materials blocked both the in and out ports of the fuel flow transducer, resulting in a complete loss of engine power. 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

During climb out, engine power reduction and total loss occurred. Instructor performed forced landing into woods; aircraft flipped inverted. Investigation found corrosive materials blocking fuel flow transducer ports.

Incident Overview

During climb out, the airplane experienced a reduction in engine power followed by a complete loss of power. The flight instructor assumed control and executed a forced landing into a wooded area. The airplane collided with trees and came to rest inverted.

Fuel System Examination

Post-accident examination of the aircraft's fuel system revealed corrosive materials present in the fuel flow transducer. The corrosive substances blocked both the inlet and outlet ports of the transducer. This transducer is part of a supplemental type certificate modification designed to measure fuel flow. It is mounted on top of the engine and is the final component in the fuel system before the fuel flow divider.

Operational History

According to the operator, the aircraft had not been flown in several years. A current annual inspection had been completed; however, there is no inspection procedure specified for the transducer assembly.

Probable Cause

The probable cause is the blockage of both the in and out ports of the fuel flow transducer by corrosive materials, which resulted in a complete loss of engine power.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X13065. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.