What happened
On 4 March 2020, a Diamond DA 42 NG Twin Star, registration G-SLCT, was performing a circuit training detail at Stapleford Aerodrome, Essex. During the initial touch-and-go on Runway 21L, the aircraft ballooned upon landing. The instructor took control of the aircraft to stabilize the ground roll, subsequently retracting the flaps and applying full power to attempt a takeoff.
As the aircraft accelerated, it moved past the transition point where the asphalt runway surface ends and the grass section begins. Although the instructor maintained full power, the aircraft failed to gain further airspeed. Deciding to abort the takeoff, the instructor reduced throttle and applied gentle braking to bring the aircraft to a stop. During the deceleration process, the nosewheel sank into the soft earth and became detached from the airframe. The nose of the aircraft subsequently dropped, causing both propellers to strike the ground before the aircraft came to a halt near the runway end. There were no injuries to the two crew members on board.
The investigation
The investigation established that recent heavy rainfall had left the ground conditions at the airfield particularly soft. The instructor noted that the aircraft was at a high weight due to being fully fuelled, and the lack of a headwind component further increased the required takeoff distance.
It was also noted that the student pilot, who was undergoing multi-engine piston rating training, had recently been flying tailwheel aerobatic aircraft. The instructor observed that the student's technique during the flare was more characteristic of tailwheel operations, which contributed to the initial ballooning of the aircraft and the extended takeoff roll.
Findings
- The aircraft transitioned from an asphalt surface to a grass surface during the takeoff roll.
- Soft ground conditions caused by recent inclement weather prevented the aircraft from accelerating sufficiently.
- The nosewheel separation occurred as the aircraft sank into the soft earth while decelerating.
- The combination of high aircraft weight, a lack of headwind, and the extended roll caused by the initial ballooning increased the takeoff distance required.