Narrative
On 16 September 2023 at 11:58 UTC, a Cessna 152, registration OK-MAJ, operated by Pondus Air s.r.o., was conducting formation training with another Cessna 152 at Poprad-Tatry Airport (LZTT). The aircraft was in the number two position, flying to the right and behind the lead aircraft. The flight was in the left-hand circuit for runway 09, before the third turn.
During the training, the engine of OK-MAJ began to exhibit sudden severe vibrations. The pilot in command (PIC), who was also an instructor, took over control from the student. He reduced engine power to idle and informed the lead aircraft that they would continue in a looser formation to land. The vibrations ceased when the engine speed dropped below 1500 rpm. The approach was made with idle power, and the landing on runway 09 was uneventful. Engine indications for oil temperature and pressure remained within normal ranges throughout.
After landing, while taxiing to the parking area, the PIC attempted to increase engine power, and the vibrations returned. After parking, the PIC reported a technical malfunction to the tower. A visual inspection revealed oil leakage in the engine compartment, specifically from cylinder number 2, where four studs connecting the cylinder to the engine crankcase were found broken.
The flight was conducted under Visual Flight Rules in daytime conditions. No injuries were sustained by the PIC or the student.
Aircraft Information
The Cessna 152 is a two-seat, single-engine aircraft primarily used for training and recreational flying. The accident aircraft, serial number 15281322, was manufactured in 1978 and registered in the Czech Republic with registration OK-MAJ. Its last 50-hour inspection was performed on 10 September 2023, and the total time since new at the time of the incident was 5809:15 hours with 10,167 cycles.
Engine Information
The aircraft was powered by a Lycoming O-235-L2C engine, serial number L-14872-15. This is a four-cylinder, horizontally opposed, air-cooled engine producing 115 hp (86 kW) standard, but modified under STC SE792NW to 92 kW (125 hp) at 2800 rpm. The engine had accumulated 1609:20 hours since overhaul at the time of the incident.
Damage
The airframe sustained no damage. The engine was extensively damaged due to the broken studs and subsequent oil leakage.