What happened
On 15 September 2001, a Europa aircraft, registration G-JAMY, was performing a private flight when it approached Kirknewton, Edinburgh, for landing. The pilot configured the aircraft with the flaps and landing gear in the down position. While the initial touchdown was smooth and uneventful, the monowheel main landing gear unexpectedly retracted shortly after the aircraft reached the ground. As the aircraft continued to roll on the partially retracted wheel, it eventually came to a stop. The incident resulted in minor propeller damage, but the pilot was able to exit the aircraft without any injuries.
The investigation
Investigators examined the mechanics of the aircraft's landing gear system, which utilizes an over-centre mechanism to maintain the gear in the locked-down position. The investigation established that if excessive play exists between the retraction lever and the retraction arm, the arm can move enough to trigger the gear's retraction even when the lever is set to the down and locked position. A key indicator of this mechanical play is a visible gap between the lever and the down-gate when the gear is properly locked.
Findings
- The primary cause of the incident was the unintended retraction of the monowheel main landing gear due to mechanical play within the over-centre mechanism.
- The gap between the retraction arm and the lever allowed the gear to move from its locked state while the aircraft was on the ground.
- A modification exists to link the retraction arm and lever with a strut to create a more rigid assembly, a feature intended for inclusion in newer construction kits by the manufacturer.