Accident Overview
On June 29, 2016, at 1930 eastern daylight time, a Cessna 150L (registration N1567Q) departed runway 31 from Atlanta Regional Airport (FFC) in Peachtree City, Georgia, on a solo instructional flight under visual flight rules. The student pilot reported that the preflight inspection, engine start, run-up, and takeoff were normal. However, at approximately 400 feet above ground level, the engine sputtered and then stopped. The pilot selected a nearby golf course for the forced landing and touched down on a slightly rolling fairway bordered by trees. During the rollout, the airplane clipped trees and struck a small berm, causing the nose landing gear to collapse. The airplane sustained substantial damage to the engine firewall. The pilot was not injured.
Engine Examination
A Federal Aviation Administration (FAA) inspector examined the airplane. The engine was rotated by hand at the propeller, and the magnetos produced spark at all eight spark plugs. A compression check confirmed thumb compression on all cylinders except the No. 3 cylinder. Upon removal of the No. 3 cylinder, severe impact damage was visible on the piston dome and cylinder head. The exhaust valve was separated at the stem, and the intake valve was fractured, with approximately 50 percent of the valve head separated. Fragments of the valves were recovered from the exhaust manifold. Both valves and associated fragments were sent to the NTSB Materials Laboratory for analysis.
Pilot Information
The pilot held an FAA student pilot certificate and a third-class medical certificate issued on December 22, 2015. She reported a total of 41 flight hours, with 38 hours in the accident airplane.
Aircraft Information
The two-seat, single-engine, high-wing Cessna 150L was manufactured in 1971 and powered by a Continental O-200 series engine. The airplane had accumulated approximately 410 hours since its last annual inspection on July 5, 2015, at a total airframe time of 3,488 hours.
Findings
Fracture analysis of the No. 3 cylinder exhaust valve revealed fatigue failure at the valve stem transition area near the valve head. The remaining fracture surfaces on the valves were due to overstress.