Accident Overview
On 24 March 2010, at approximately 1038 hours UTC, a Diamond DA 42 Twin Star, registration G-CDKR, was involved in a takeoff accident at Crossland Moor Airfield near Huddersfield, Yorkshire. The aircraft was operated on a private flight with a single pilot and no passengers. The pilot, aged 25, held a Commercial Pilot's Licence and had 1,213 total flying hours, including 70 hours on the accident aircraft type. His recent flying experience was limited: 17 hours in the last 90 days and 2 hours in the last 28 days.
Pre-Takeoff Preparations
The pilot planned to depart from Runway 25 to Elstree Aerodrome. Runway 25 consists of 600 meters of asphalt with an additional 250 meters of grass at its upwind end. The pilot's performance calculations accounted for a 2.6% upslope, resulting in a still-air Take Off Distance Required (TODR) of 528 meters to a height of 50 feet, with a ground roll of 363 meters. The surface wind was estimated from 190° at 13 knots, providing a 7-knot headwind, which the pilot calculated reduced the TODR and ground roll by approximately 20 meters. The aircraft's takeoff weight was 1,603 kg, with the center of gravity in the middle of the flight range. All flying control trims were set to the takeoff position.
The pilot conducted a thorough pre-flight inspection with no defects identified. Engine start and associated checks, including the trim system, autopilot, and elevator variable backstop, were normal. He backtracked Runway 25 to use the full length. The takeoff technique followed the Aeroplane Flight Manual (AFM): flaps retracted, full power selected before brake release. Both engines developed expected full power, with 2340-2350 rpm indicated. The pilot reported nothing unusual at that stage.
Takeoff and Rotation Failure
The aircraft achieved the planned rotation speed (VR) of 70 knots with approximately 100 meters of paved runway remaining. The pilot attempted to rotate but reported no perceptible pitch change. After cross-checking the airspeed, now 75-80 knots, with the right seat airspeed indicator, he attempted rotation again with no response. As the aircraft crossed from the paved to grass surface, he made a third unsuccessful rotation attempt. The increased drag from softer grass reduced acceleration, and speed remained at around 75-80 knots. The pilot then rejected the takeoff, selecting idle power and applying brakes. As the aircraft neared the runway end, he turned right at about 50 knots, causing the aircraft to slide sideways into a gulley in the runway overrun.
Post-Accident Actions and Damage
The pilot shut down both engines, turned off fuel, isolated electrical supplies, and evacuated via the main canopy, uninjured. The aircraft sustained extensive damage, including a fuselage fracture behind the cockpit, detachment of the aft fuselage, collapsed landing gear, shattered propellers, and left wing damage. The cockpit area remained intact, protecting the pilot. No fire occurred.
Investigation Findings
Following the accident, no technical or operational deficiencies could be identified. The aircraft manufacturer's UK representative conducted a limited survey, including inspection of the elevator control runs. Although the pushrod was deformed by fuselage damage, no other defects were found. The right engine Electronic Control Unit (ECU) was downloaded and revealed no anomalies; the left engine ECU could not be downloaded due to accident damage. The pilot's pre-flight and pre-takeoff checks were normal, and the AFM performance data for takeoff over a 50-foot obstacle requires the available runway length to be at least equal to the takeoff distance. The DA42 AFM notes that an uphill slope of 2% increases takeoff distance by approximately 10%. The pilot considered that local wind effects may have been involved, although turbulence is usually experienced with northerly winds.
The investigation was unable to determine why the aircraft would not take off. No probable cause was identified.