What happened
On 1 May 2009, a Yak-52, registration G-OCBT, was performing a private flight returning to Little Gransden Airfield, Cambridgeshire. The pilot had been conducting aerobatic maneuvers in the airfield overhead for approximately 20 minutes before joining the downwind circuit for landing.
During the approach, the pilot attempted to extend the landing gear. While moving the lever from the UP position, the pilot selected the three-position lever to what was believed to be the DOWN position. However, the lever was actually moved to the NEUTRAL position. The pilot noted that the sound of pneumatic operation, which typically accompanies gear extension, was heard, leading to the belief that the gear had deployed.
As the aircraft approached the runway, the propeller shattered and passed the right side of the aircraft. The aircraft subsequently touched down with the landing gear retracted. Upon completing the landing, the pilot discovered that the gear lever remained in the NEUTRAL position and that the landing gear indicators had not been verified.
The investigation
The investigation focused on the sequence of gear lever manipulation and the pilot's perception of the gear's status. The pilot reported that the transition from high-workload aerobatics to the landing circuit contributed to the error. It was noted that the pilot had recently been operating a different aircraft type featuring a two-position landing gear lever, which may have influenced the handling of the three-position lever on the Yak-52.
Findings
- The aircraft landed with its landing gear in the retracted position.
- The pilot moved the landing gear lever from UP to NEUTRAL instead of DOWN.
- The pilot did not check the landing gear position indicators prior to touchdown.
- The pilot's belief that the gear had extended was based on hearing the pneumatic 'hiss' of the system, which occurred during the lever movement.
- The pilot's attention was divided due to the high workload of transitioning from aerobatic flight to the landing circuit.
- The propeller, airframe, and landing gear up locks sustained damage, and the engine was shock-loaded.