What happened
On 24 April 2010, a Yak-52, registration G-YKCT, was conducting a dual recurrent training session near Kilkerran Airstrip in Ayrshire. The flight profile included various maneuvers such as stalls, spins, and aerobatics, followed by planned circuit work.
During the first scheduled go-around of a normal approach, the crew applied full power. Although the RPM gauge initially indicated 100% power, the crew soon experienced vibrations and a noticeable drop in engine performance accompanied by fluctuating RPM readings. Because the aircraft failed to climb effectively and obstacles were present on the flight path, the pilot decided to perform a gear-up, flapless forced landing in a field situated to the right of the runway centerline. The aircraft landed on short grass, which resulted in no injuries to the two crew members.
The investigation
The AAIB examined the aircraft and the site of the landing. The investigation noted that the design of the Yak-52 allows for landings with the gear retracted without significant structural damage, as the wheels remain partially exposed from the fuselage and wings. The landing gear and flaps had been raised by the crew to maintain airspeed during the descent.
Upon inspection of the landing site, no water was found on the grass. The engine was subsequently removed and sent to a specialist for a detailed examination to identify any potential causes for the power loss. This inspection revealed no mechanical faults capable of explaining the reduction in power.
Findings
- The aircraft sustained damage to the propeller, the right main landing gear oleo strut, and the uplock mounts.
- The primary cause of the forced landing was a reduction in engine power and fluctuating RPM.
- The decision to execute a gear-up landing was necessitated by the lack of a climb rate and the presence of obstacles ahead.