Incident Overview
On 22 July 2020, a Cessna 152 aircraft, registration SP-KOG, was involved in an incident at EPBC (Warsaw Babice Airport). The aircraft was conducting training flights for a Private Pilot License (PPL(A)) with an instructor and a student pilot on board.
Sequence of Events
At 08:06 LMT, after departure from runway 28L, the instructor noticed uneven engine operation. He immediately reported the situation to 'Babice Radio' and requested permission to fly the southern traffic pattern. In response, air traffic control offered the option to land on runway 10L (a downwind landing), which the instructor accepted. The landing was completed at 08:11 with the assistance of airport services. No further consequences resulted from the event. The crew subsequently taxied the aircraft to the Aeroklub Warszawski hangar. The malfunction was recorded in the aircraft's technical log.
Cause of the Incident
The investigation determined that the incident was caused by the shearing of bearing cap fasteners under one of the connecting rods. This failure allowed the bearing shells to rotate together with the connecting rod, resulting in wear to the crankshaft.
Contributing Factors
No contributing circumstances were identified by the investigation.
Recommendations
The maintenance organization sent the engine components to the manufacturer for further verification. No additional safety recommendations were formulated.