What happened
On May 29, 2016, a Cessna 152 was performing a takeoff from runway 08 at Warsaw-Modlin Airport (EPMO). Shortly after departing the runway, the pilot-in-command noticed fluctuations in the engine revolutions per minute (RPM).
In response to the engine instability, the pilot decided to perform a straight-in landing back at the departure airfield. The aircraft landed safely without further incident. Following the landing, the operator suspended all operations involving the aircraft until a mechanical inspection could be completed.
The investigation
The investigation focused on the mechanical state of the engine following the reported fluctuations. During the inspection, a mechanic examined the engine components and identified contaminated spark plugs. After the spark plugs were cleaned, the mechanic performed three separate engine test runs. No further irregularities or malfunctions were detected during these tests, and the aircraft was subsequently cleared to return to service.
Findings
- The primary cause of the engine fluctuations was the contamination of the spark plugs.