What happened
On 8 April 2018, a Yakovlev Yak-18, registration F-AZYK, was participating in a vintage aircraft rally at Lens Bénifontaine Aerodrome in France. After completing a flight over local memorials, the pilot began a return flight. While performing an aerodrome traffic pattern, the pilot executed a series of maneuvers at a very low altitude. The aircraft began a left half-roll followed by a descending half-loop. During this sequence, the aircraft struck the ground at the threshold of runway 03. The impact, which occurred with significant energy in a nose-down attitude, resulted in two fatalities (the pilot and one passenger) and the destruction of the aircraft.
The investigation
The investigation focused on the technical state of the aircraft, the pilot's experience, and the regulatory context of the event. Examination of the wreckage confirmed the engine was producing power at the moment of impact and the rudder control system was intact. Analysis of video recordings and audio from the scene showed the aircraft was traveling at speeds exceeding 110 knots and that the engine was operating at approximately 86-88% power, with no signs of mechanical failure.
Investigators also examined the nature of the rally. While the organizers did not classify the event as an official air show—and therefore did not seek formal authorization from the civil aviation authority—the presence of the public was significant. Spectators were located in nearby parking areas and on access roads, with the aircraft's final path passing just 40 meters from numerous people.
Findings
- The primary cause of the accident was the execution of an aerobatic maneuver at an insufficient altitude, which left no safety margin to avoid ground impact.
- The pilot lacked sufficient recent experience with this specific aircraft type and the local aerodrome environment to safely perform such figures.
- The aircraft's flight path over a populated area, combined with the lack of a formal safety study (as the event was not classified as an air show), significantly increased the risk of a mass-casualty event.