Incident Overview
On May 8, 2015, a Cessna 172S aircraft, operating a training flight near Warsaw-Babice Airport (EPBC), experienced engine vibrations shortly after takeoff. The aircraft was occupied by two individuals, both uninjured.
Sequence of Events
Before departure, an engine run-up was performed and showed normal operation. After takeoff, at approximately 150 feet above ground level, the engine began to vibrate, although engine instrument readings remained unchanged. The pilot-in-command, who held an airline transport pilot license, notified Babice Radio of the situation and climbed to 1,000 feet. After executing a 180-degree turn, the pilot coordinated a landing clearance and landed without further issues.
Post-Flight Inspection
Upon taxiing off the runway, the pilot conducted another engine run-up, which again indicated normal engine performance. The aircraft was then taxied to the hangar and handed over to the technical department. A description of the vibrations was entered into the aircraft technical log.
Maintenance Actions
An engine inspection was performed, and the spark plugs were replaced. Following the replacement, the engine operated normally. In subsequent flights, no vibrations recurred.
Probable Cause
The incident was attributed to engine vibrations during flight, likely caused by a malfunctioning spark plug or spark plugs.