What happened
On Saturday, November 10, 2001, a Yakovlev Yak 52, registration RA 02705, was completing a local flight at Lognes aerodrome. After a flight of approximately thirty minutes, the pilot performed a landing on runway 08, approaching from a tailwind position.
Following the touchdown, the aircraft rolled for approximately 500 meters before the pilot applied the brakes. As the aircraft reached 150 meters from the end of the runway, traveling at a speed of roughly 20 km/h, it experienced a left-hand ground loop. The aircraft eventually came to a halt on the grass bordering the runway. The incident resulted in slight damage to the aircraft due to the collapse of the left main landing gear.
The investigation
The investigation focused on the mechanical failure of the landing gear and the maintenance procedures for the aircraft. Investigators determined that the left main landing gear had collapsed because the locking mechanism had seized.
Technical analysis revealed that the seizure was caused by a lack of lubrication within the mechanism. The pilot, who was a recent owner of the aircraft, noted that the specific type of actuator used in this model does not feature an integrated grease fitting. Consequently, lubrication requires the removal and disassembly of the actuator. Without performing this disassembly, it is impossible to verify the adequacy of the lubrication within the mechanism.
Furthermore, the investigation examined the technical documentation and oversight of the aircraft. The aircraft's airworthiness certificate is renewed annually by the Russian regulatory authority. While the pilot possessed technical documentation translated from Russian into English, this translation had not been officially approved by the Russian authorities. The owner also noted significant difficulties in communicating with relevant parties to obtain precise, up-to-date technical information and maintenance documentation necessary for regular upkeep.