What happened
On June 1, 2016, a Vans RV-4, registration PH-EIL, was performing a routine flight from the private airfield of Coëx – La Boissière to the Sables d’Olonne – Talmont. After a brief refueling stop at the destination, the pilot and a passenger departed for the return flight to Coëx.
During the final approach to runway 01, while executing a right-hand turn at an estimated altitude of 600 feet, the engine lost power. The pilot attempted to correct the flight path by initiating a left-hand turn to avoid obstacles. During this maneuver, the aircraft struck trees and subsequently impacted the ground in a field approximately 400 meters from the airfield. The impact resulted in one fatality (the pilot) and one serious injury (the passenger). The aircraft was destroyed.
The investigation
The BEA investigation focused on the electrical system and the recent maintenance performed on the aircraft. Several days prior to the accident, a mechanic had replaced the traditional magnetos with two electronic ignition devices. During this installation, the engine RPM indicator ceased to function, a defect the pilot was aware of but chose to fly with. Additionally, the alternator had not been reconnected due to a damaged circuit breaker, meaning the battery was not being charged during flight.
Investigators also examined the aircraft's Emergency Locator Transmitter (ELT). Although the aircraft was registered in the Netherlands, the ELT still contained outdated registration data from its previous life in the United States (N921MS). This discrepancy caused significant delays in the search and rescue operation, as the initial distress signal was incorrectly associated with a non-existent American aircraft.
Findings
- The engine failure was likely caused by an electrical power supply failure to the electronic ignition devices, or a depleted battery, combined with an engine RPM that had dropped below the threshold required for the devices to operate autonomously.
- The pilot was unable to monitor the engine's RPM due to the non-functional instrument.
- The maintenance management system for amateur-built aircraft, which relies on self-declaration, allowed the aircraft to fly despite known equipment malfunctions.
- The pilot's decision to turn left likely aimed to reach an open field, but the low altitude and presence of obstacles made an effective recovery maneuver difficult.