What happened
On February 1, 2004, at approximately 15:53, a Pottier P 180 S amateur-built aircraft, registration F-WRCE, was performing a flight test at the Chambéry Challes-Eaux aerodrome. After departing from runway 33, the aircraft completed an acceleration level-off before entering a steep climb. Witnesses observed the engine experiencing misfires followed by a complete failure at an altitude estimated between 75 and 100 meters, roughly 300 meters from the runway end.
Following the engine loss, the pilot attempted to execute a turn to return to the runway. During this maneuver, the aircraft descended into a right-hand turn and struck a building at a 45-degree nose-down angle. The impact caused the aircraft to catch fire, resulting in the destruction of the aircraft and the death of the pilot.
The investigation
The investigation focused on the cause of the engine failure and the pilot's inability to perform an emergency landing. The aircraft was powered by a Rolls Royce Continental C90-14F engine, which had been installed approximately 5 hours and 45 minutes prior to the accident. The pilot had been conducting flight tests to fulfill requirements for a permanent certificate of airworthiness.
Investigators examined the fuel system, noting that the aircraft utilized a flat-bottom fuel tank. The fuel pickup was located in the center of the tank floor, and the gauging system had not been calibrated. While the fuel circuit showed no signs of contamination, the exact amount of fuel remaining in the tank could not be determined. The engine examination revealed that the carburetor was equipped with an air box lacking a heater, and the main jet was oversized. Due to the extent of the wreckage destruction, investigators could not definitively confirm whether the failure was caused by fuel starvation or carburetor icing.
Findings
- The engine failure occurred during a period of high-power climb, which may have led to fuel starvation if the aircraft's pitch attitude caused the fuel level to drop below the pickup point.
- Atmospheric conditions were conducive to carburetor icing during a full-power climb.
- The decision to conduct flight tests in a direction that did not allow for a safe emergency landing was a critical factor, as the surrounding industrial buildings prevented a successful return to the runway.