Engine Cylinder Separation During Climb Following Fatigue Cracking (N4803D)

Event Description

Witnesses observed the single-engine airplane's takeoff and climb as normal. As the airplane climbed through approximately 400 feet, a puff of black smoke was seen emanating from the right side of the engine compartment. The airplane then nosed up slightly, followed by a nosedown attitude with a turn of about 360 degrees before descending rapidly from view. One witness heard the engine start missing before the airplane turned and descended. Flight control continuity was established to all controls.

Engine Examination

Post-event examination of the engine revealed that the #6 cylinder head had separated from its cylinder barrel. The separation was a result of fatigue cracking that originated in the cylinder head threads. The engine had been overhauled about 353.86 hours prior to the event, during which six Nu-chromed overhauled cylinders were installed. It could not be determined how many hours the cylinders had accumulated or how many times they had been overhauled. There is no requirement to track cylinder hours or overhaul occurrences.