What happened
On August 16, 2006, at 17:50, a Pottier P 230 S aircraft, registered F-PARS, was conducting a local flight near Villette-les-Arbois. The pilot departed from Dôle aerodrome at 17:20. Witnesses on the ground observed the aircraft descending over the runway at Arbois aerodrome at an altitude between 50 and 100 meters. As the pilot attempted to climb, engine misfires were heard. The aircraft then entered a steep right-hand turn while descending, at which point the engine ceased operation. The aircraft subsequently struck a hedge approximately 400 meters north of the aerodrome and crashed.
Two fatalities occurred during the impact, and the aircraft was destroyed.
The investigation
Investigators examined the wreckage and found the engine was not producing power at the time of impact. While the carburetor contained fuel, the right fuel tank was ruptured during the crash, and the left tank contained a small amount of fuel. The fuel selector was set to the left tank.
Analysis of the aircraft's maintenance logs revealed that the pilot had previously recorded an issue regarding fuel starvation during descents, noting that while the left tank functioned during level flight, it would cut out during descents.
Further technical examination of the fuel system revealed that the aircraft's tanks had been modified from the manufacturer's original design. While the designer's specification includes an L-shaped baffle to manage fuel, the left tank on F-PARS lacked this baffle. Additionally, only the rear suction point was connected to the fuel line, which was positioned only one centimeter above the bottom of the tank.
Findings
- The pilot elected to continue flight operations despite an unexplained and previously documented engine malfunction.
- The pilot performed low-altitude maneuvers without accounting for the known fuel delivery anomalies.
- The lack of a baffle in the modified left fuel tank likely caused fuel starvation during descent maneuvers.
- The pilot possessed insufficient knowledge regarding the specific operational characteristics and risks associated with the aircraft's modified fuel system.