Accident Details
On 7 January 2014 at 1611 UTC, a Diamond DA 42 Twin Star (registration G-CTCH) operated by an undisclosed training organisation was conducting a training flight at Exeter Airport, Devon. The instructor, a 63-year-old holder of a Commercial Pilot's Licence with 8,347 total flying hours (2,200 on type), was supervising a student pilot. There was also one passenger on board. Neither crew nor passenger sustained injuries.
Sequence of Events
After the student performed a landing described as "competent," the instructor intended to execute a go-around. He reached for the flap switch to retract the flaps to the takeoff setting but inadvertently moved the landing gear lever to the up position. Although he quickly realised the mistake and returned the lever to down, the right main landing gear had already unlocked and collapsed at an airspeed of about 60 kt. The aircraft yawed to the right, departed the runway, and travelled onto grass before coming to a stop.
Damage
The accident resulted in damage to the right wing tip, right aileron, tail skid, and the right propeller.
Findings
The aircraft is equipped with a weight-on-wheels switch on the left oleo, which is designed to prevent gear retraction while on the ground. The investigation noted that at 60 kt, with landing flap selected and a crosswind component from the left, the aircraft likely became very light on the left side, preventing the weight-on-wheels switch from activating. The pilot stated that he had performed the go-around procedure "hundreds of times" and attributed the accident to a reduction of his alertness, possibly due to his confidence in the student's ability.