What happened
On May 29, 2016, a student pilot was performing a solo flight departing from Pruszcz Gdański Airport (EPPR). Prior to takeoff, a routine engine test was conducted without any noted issues. After the takeoff and following the completion of the first turn at an altitude of approximately 600 feet, the pilot realized the aircraft was unable to maintain a climb.
In response to the loss of performance, the pilot executed a circuit and returned to the departure airfield. The landing was completed successfully and without further incident. There were no injuries reported during the event.
The investigation
Following the incident, the aircraft was inspected by a mechanic. The technical examination revealed that the lower spark plug in cylinder number 4 was malfunctioning due to electrode fouling (short-circuiting). The faulty spark plug was replaced with a new component. Subsequent engine tests performed after the replacement showed that the engine was operating normally, with no further anomalies detected.
Findings
- The primary cause of the incident was the fouling of the lower spark plug in cylinder number 4.
- The fouling was likely caused by the engine operating at idle speeds for an excessively long duration.