What happened
On 26 August 2012, a Pioneer 400, registration G-TLOY, was performing the fifth in a series of test flights for the purpose of obtaining an initial Permit to Fly. The flight was being conducted at Ledbury Airstrip in Herefordshire. During the flight, the pilot experienced a loss of pitch control authority while attempting a go-around at low speed. In an effort to manage the situation and ensure a safe landing, the pilot delayed the extension of the landing gear.
Upon touchdown, the landing gear was not fully extended, which caused the gear to collapse during the landing roll. This resulted in the propeller striking the ground and caused damage to the underside of the aircraft and the landing gear jackscrews. There were no injuries to the pilot or the passenger on board.
The investigation
The investigation examined the aircraft' and its control systems. It was noted that prior to this flight, half of the Gurney flap on the elevator trim tab had been removed to address a perceived lack of forward elevator authority during cruise. Post-accident inspections of the aircraft at the distributor's premises found no pre-existing defects in the airframe or controls.
Investigators found that the landing gear failure was due to the gear not being fully extended at the time of landing. While a slight stiffness was noted in the elevator, and the elevator cables were found to have low tension, it was uncertain if this low tension was present at the time of the accident or caused during the post-accident disassembly process. Subsequent flight testing by the LAA Chief Test Pilot, using the aircraft in its standard configuration, confirmed the design was acceptable and that sufficient control authority remained for safe operations.