What happened
On 23 March 2011, a Piper PA-28R-180 Cherokee Arrow, registration G-AVYT, was conducting a private flight involving several touch-and-go circuits at Gamston Airfield. The pilot proceeded to Sturgate Airfield in Lincolnshire to complete further circuits before landing for refueling.
During the downwind leg for Runway 27, the pilot manually selected the landing gear to the down position and observed that the three green indicator lights had illuminated, suggesting the gear was locked. However, as the aircraft entered the landing flare, the landing gear began to extend. This resulted in the aircraft making contact with the runway with the gear partially retracted, causing damage to the propeller tips, the lower surface of the aircraft, and a shock-load to the engine.
The investigation
The AAIB investigation examined the aircraft's mechanical systems and the pilot's actions. It was established that the aircraft was equipped with an automatic backup gear extender designed to lower the landing gear if the airspeed falls below 95 kt and engine power is reduced to idle. However, investigators found that this specific backup system had been inhibited on G-AVYT.
Findings
- The pilot believed the landing gear was securely locked based on the illumination of the green indicator lights.
- The landing gear actually began its extension late in the landing flare.
- The automatic backup gear extension system was inhibited on the aircraft.