Incident Overview
On 16 March 2016, a Cessna 152 aircraft (registration not specified) was conducting a training flight at Depułtycze Królewskie airfield (EPCD). The crew consisted of an instructor and a student pilot. The flight was a training session focusing on the student's response to engine failure and simulated emergency landing. After completing the third simulated engine failure and landing, during the landing roll, the engine shut down automatically. The crew attempted to restart the engine twice with no success. They then shut down all systems and manually pushed the aircraft to the parking position, clearing the runway. The event was recorded in the aircraft technical log.
Investigation Findings
The investigation determined that the preceding flights (including the simulated failures) were performed at reduced power with gliding segments. This led to carbon buildup on the spark plugs and weakened spark. Additionally, the mixture may have been overly rich, causing spark plug fouling. Because the flights were short and consecutive, neither the carbon nor excess fuel had a chance to burn off. It was also found that the ignition timing was not incorrect (i.e., it was within specifications). The combination of these factors accumulated over successive flights and resulted in the engine shutting down after one of the landings.
Corrective Actions
After the incident, all spark plugs were replaced and the ignition timing was adjusted. The aircraft was subsequently released for service. The operator took the following preventive measures: 1. Simulated engine failure exercises must conclude with a full stop landing rather than an immediate touch-and-go. 2. If more than one simulated failure is required, each must be a full stop followed by taxi to the threshold. 3. Before occupying the runway for the next takeoff, the pilot should run the engine at high power to clear and dry the spark plugs ("burn off").
No safety recommendations were issued by the investigation commission.