Casualties unknown

Engine failure due to exhaust valve failure results in gear-up landing (N7892R)

Seymour, IN, US

On June 23, 1988, a Beech V35A (registration N7892R) was involved in an aviation accident near Seymour, IN. Investigators recorded the probable cause as: The failure of the number 2 exhaust valve, which became wedged between the cylinder and piston top, cracking the cylinder head at the barrel threads. 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 cruise flight at 6500 feet, an engine began running rough. The pilot navigated to the nearest airport and executed an intentional gear-up landing with cruise power.

What happened

The aircraft was operating in cruise flight conditions at an altitude of 6500 feet when the engine began to run roughly. Recognizing the mechanical issue, the pilot navigated toward the nearest available airport. Upon arrival, the pilot executed an intentional gear-up landing while maintaining cruise power settings.

The investigation

A postcrash examination of the aircraft revealed that the number 2 exhaust valve had failed. The component became wedged between the cylinder and the top of the piston. This mechanical interference caused a crack in the cylinder head specifically at the barrel threads.

Findings

The primary factor contributing to the incident was the failure of the number 2 exhaust valve. This failure led to the valve becoming lodged between the cylinder and piston, resulting in structural damage to the cylinder head.

Probable cause

The failure of the number 2 exhaust valve, which became wedged between the cylinder and piston top, cracking the cylinder head at the barrel threads.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X25889. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.