Incident
On July 12, 2023, at Nowy Targ Airport (EPNT) in Poland, a Cessna 152 (registration SP-KER) sustained damage after an engine compartment fire during starting. The aircraft was occupied by a flight instructor and a student pilot. The student had declined to perform a planned solo cross-country flight after two unsuccessful engine start attempts. Following the second attempt, smoke appeared but the instructor considered it normal and proceeded with two additional starts.
Sequence of Events
According to the investigation report by the Polish State Commission on Aircraft Accident Investigation (PKBWL), the instructor’s starting technique involved an excessive number of fuel priming injections before each attempt and extensive throttle movements between 75% and 100% after engaging the starter. The aircraft’s Pilot’s Operating Handbook does not permit such throttle manipulation. During the fourth start attempt, fuel vapors in the engine compartment ignited, producing smoke and flames. The crew evacuated the cockpit and extinguished the fire using onboard fire extinguishers. No injuries were reported, but the aircraft was damaged.
Cause and Contributing Factors
The investigation determined that the cause of the fuel vapor ignition was engine starting performed in a manner inconsistent with the aircraft’s Flight Manual. Contributing factors included the instructor’s disregard of smoke that appeared during the second start attempt, continuation of starting despite indications of a potential fire, and the instructor’s use of an unapproved, incorrect starting technique involving excessive fuel priming and throttle pumping.
Safety Actions
The operator of the aircraft proposed preventive measures, including discussing the incident among club pilots flying Cessna 152/172 aircraft and addressing the event during a safety conference before the 2024 season, focusing on the disregard of procedures and safety principles. The PKBWL accepted these actions and issued no additional safety recommendations.