What happened
On April 24, 2011, a Yak 52, registration RA-3619K, departed from Lognes airfield for a local flight. The pilot intended to attend a Yak aircraft gathering scheduled for the following day at La Ferté-Alais. During the flight, the pilot coordinated with another Yak 52 pilot via radio to meet east of the airfield facilities, specifically near the Fontenay-Trésigny aerodrome.
Upon arrival at Fontenay-Trésigny, the pilot announced an intention to perform low-altitude flypasts of runway 12. An instructor pilot observing the flight estimated the aircraft's altitude to be between 50 and 100 feet. While the second aircraft was preparing for a subsequent pass, the pilot observed the first aircraft enter a steep climb before disappearing from view. Shortly thereafter, while established on the downwind leg, the pilot of the second aircraft witnessed the RA-3619K strike the ground. Ground witnesses also reported seeing the aircraft deviate to the right before pitching downward into the terrain.
The investigation
Investigators examined the wreckage and determined that the aircraft struck the ground in a steep dive with a right-hand bank. Detailed inspections of the control surfaces and the control linkage revealed that all structural failures were the result of the impact; no pre-existing damage was found, and the engine was producing power at the time of the accident.
While the aircraft had been involved in a previous accident approximately one year prior, no mechanical failures were identified as a cause for this occurrence. The aircraft was equipped with tandem dual controls, and investigators were unable to determine which occupant was operating the controls at the moment of impact. Autopsies of the pilot and passenger revealed no medical conditions that contributed to the accident.
Additionally, the investigation noted a lack of oversight regarding the maintenance programs for Russian-registered aircraft operating under French laissez-passer status, as the Russian civil aviation authority no longer recognized the Federation of Private Aviators (FLA) as the responsible body for airworthiness and licensing oversight.