Incident Overview
On 12 June 2019, at approximately 17:30 UTC, a student pilot was conducting a cross-country flight in a Cessna C-150 at Nowe Miasto Airport (EPNM). While flying at an altitude of 1,500 feet, the pilot reduced engine RPM to decrease airspeed to 90 knots. Shortly thereafter, the engine began to run unevenly, and RPM spontaneously dropped from 2,500 to 2,000, despite all engine parameter indications remaining within the green arc.
Pilot Actions
The student pilot then pulled the carburetor heat lever. Following this action, the engine RPM stabilized at approximately 2,100 RPM. However, due to insufficient engine power, the aircraft descended 100 feet while maintaining an airspeed of 70 knots. Upon instruction from the supervising instructor, the student executed a landing procedure as if with a failed engine and safely landed without further incident.
Investigation Findings
The investigation determined that the cause of the incident was a fracture of the exhaust valve pushrod in one of the engine's cylinders. No injuries were reported; the sole occupant (the student pilot) was uninjured. The aircraft sustained no damage.
Recommendations
The investigation commission did not issue any safety recommendations.