FlightFinder
Check my flight
Casualties unknown

Engine Malfunction Leads to Forced Landing After Intake Valve Issues (N8599U)

Wyandotte, IN, US

On July 22, 1995, a Cessna 172F (registration N8599U) was involved in an aviation accident near Wyandotte, IN. Investigators recorded the probable cause as: the number three intake valve became stuck (seized), which resulted in a loss of engine power. The lack of suitable terrain for a forced landing was a related factor. 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 2026-07-04Data APIEditorial standards

During flight, the engine began popping and dropped to 1,400 RPM. Despite switching fuel tanks and applying carburetor heat, the engine did not recover. The pilot attempted a forced landing in a wheat field, but the airplane sustained substantial damage upon impact. Examination revealed carbon deposits under the intake valve seat and scratches on the valve stem of cylinder number three, with compression loss in that cylinder.

Incident Overview

The pilot-rated passenger reported that the engine began to 'pop' and the engine speed dropped to 1,400 RPM. The pilot switched fuel tanks and applied carburetor heat, but the engine did not recover. The airplane was over hilly/forest terrain with only a small wheat field available.

Forced Landing Attempt

During an attempted forced landing, the pilot made a 50-degree turn to align the airplane with the field. The airplane impacted the terrain and sustained substantial damage to the fuselage, wings, and empennage.

Post-Accident Examination

A compression check revealed compressions of 50, 55, 10, 66, 62, and 58 pounds per square inch in cylinders one through six, respectively. During the check of the number three cylinder, air could be heard flowing into the intake manifold. Examination of the number three intake valve revealed 'considerable' carbon under the intake valve seat and scratches in the valve stem.

Frequently asked questions

What happened in the 22 Jul 1995 Cessna 172F accident near Wyandotte, IN?

During flight, the engine began popping and dropped to 1,400 RPM. Despite switching fuel tanks and applying carburetor heat, the engine did not recover. The pilot attempted a forced landing in a wheat field, but the airplane sustained substantial damage upon impact. Examination revealed carbon deposits under the…

What aircraft was involved and where did it happen?

The accident on 22 Jul 1995 involved a Cessna 172F, registration N8599U, at Wyandotte, IN.

What was the probable cause of the accident?

the number three intake valve became stuck (seized), which resulted in a loss of engine power. The lack of suitable terrain for a forced landing was a related factor.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001207X03903. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.