What happened
A Cessna 172M, registration C-GSZC, was performing a visual flight rules flight from Sept-Îles to Rivière-du-Loup, Quebec, when the pilot decided to proceed toward Québec without refueling. After dropping off passengers at Rivière-du-Loup, the pilot began the final leg of the journey. During the flight, weather conditions worsened due to rain showers and mist, prompting the pilot to request special VFR clearance to land at the Québec Airport.
Approximately nine nautical miles from the threshold of Runway 2-4, the Lycoming engine began to sputter and eventually ceased operation. The pilot declared an emergency and was directed by air traffic control to land on the de la Capitale highway. During the forced landing, the aircraft struck a street lamp and the nose of the plane dropped before impacting the ground. The pilot sustained serious injuries, and the aircraft was severely damaged.
The investigation
The investigation focused on the cause of the engine failure and the pilot's flight planning. Investigators examined the aircraft's fuel tanks and the engine, finding no mechanical or technical defects that would have caused the engine to stop. Laboratory analysis of the fuel tanks confirmed that the engine stopped due to fuel exhaustion.
Investigators also reviewed the pilot's planning process. The pilot, who was completing a cross-country flight for a commercial pilot licence, had not consulted the Cessna 172 flight manual to verify the aircraft's endurance. Based on an incorrect assumption that the aircraft could fly for six hours, the pilot believed the remaining fuel was sufficient to reach Québec, despite having already flown 3.4 hours on the previous leg.
Findings
- The engine stopped because the aircraft ran out of fuel.
- The pilot failed to use the aircraft flight manual to accurately calculate the required fuel for the flight leg.
- The pilot's estimate of the aircraft's flight endurance was inaccurate, as the actual endurance at the operating conditions was significantly lower than the assumed six hours.