What happened
On August 6, 2008, at approximately 16:30 UTC, a Cessna A152 departed from Graz Airport for a non-commercial flight under Visual Flight Rules (VFR). The aircraft was carrying a pilot and one passenger. During the initial climb phase, the pilot detected an engine malfunction and attempted to execute a turn to return to the airport. Shortly thereafter, the engine suffered a complete failure. Unable to maintain flight, the pilot performed an emergency landing in a cornfield south of the airport near Kalsdorf/Graz.
The impact resulted in two light injuries (the pilot and the passenger) and caused substantial damage to the aircraft.
The investigation
The Austrian Federal Safety Investigation Board (SUB) conducted an examination of the wreckage and the aircraft's maintenance history. Investigators focused on the mechanical condition of the engine, specifically examining the cylinder components and the lubrication system. The investigation included a detailed analysis of the fourth cylinder, the connecting rod, and the oil filter to identify any internal component failures or foreign object damage.
Findings
Technical analysis of the engine revealed that the intake valve tappet of cylinder number 4 had broken at the transition between the tappet shaft and the tappet face. This failure was characterized by a forceful fracture. The investigation also identified evidence of foreign object damage within the combustion chamber and significant material erosion on the piston. Furthermore, metallic particles were discovered within the single-use oil filter, indicating internal engine degradation. These mechanical failures led to the total loss of engine power during the climb.