What happened
On September 19, 1997, a Rans S-6S “Super” Coyote II kitplane, registration PH-2T7, crashed approximately 5 km southwest of Lelystad airport. The aircraft was on a local flight when the engine began to sputter. Witnesses observed the aircraft descending in a nearly vertical nose-down attitude, spinning around its longitudinal axis before striking a beet field. The impact caused the wings to break forward and resulted in the fatal death of the pilot.
The investigation
Investigators examined the wreckage and the aircraft's fuel system. The aircraft was a self-built kitplane. While the engine and mechanical controls for the ailerons, elevators, and rudder were found to be in working order, the fuel system revealed that the left wing tank was empty. The right wing tank and the cabin tank both contained approximately 18 liters of fuel. The investigation also included a post-mortem examination of the pilot, which identified the presence of phenobarbital, a medication used for migraines, in the bloodstream.
Findings
Analysis of the fuel levels indicated that the pilot had been flying using the left wing tank, which eventually ran dry. When the engine began to fail, the pilot likely attempted to rectify the situation by opening the fuel valve for the cabin tank. However, this action was likely performed too late to maintain engine power. During this process, the pilot likely failed to maintain sufficient airspeed, leading to an aerodynamic stall and loss of control.
The pilot's attention was likely diverted from flying the aircraft to managing the fuel system.
Contributing factors included the potential for surprise, as the aircraft had departed with adequate fuel. Furthermore, the presence of phenobarbital, which can cause drowsiness and reduced reaction times, may have contributed to the pilot's failure to monitor fuel levels or respond promptly to the engine malfunction.