What happened
On 24 March 2010, a Diamond DA 42 Twin Star, registration G-CDKR, was preparing for a private flight from Crossland Moor Airfield to Elstree Aerodrome. The pilot elected to use Runway 25, which features a 600 m asphalt surface followed by a 250 m grass section. Following a standard pre-flight inspection and engine start, the pilot backtracked to use the full length of the runway.
During the takeoff roll, the pilot applied full power with flaps retracted. The aircraft reached the planned rotation speed of 70 kt with approximately 100 m of paved runway remaining. However, upon attempting to rotate, the pilot experienced no perceptible pitch change. Despite a second attempt at a higher airspeed of 75-80 kt, the aircraft failed to respond. As the aircraft transitioned from the asphalt to the grass portion of the runway, increased drag prevented further acceleration. The pilot subsequently rejected the takeoff by selecting idle power and applying the brakes. As the aircraft reached approximately 50 kt near the end of the runway, it veered to the right and slid into a nearby gulley.
There were no injuries to the pilot, though the aircraft was damaged beyond economic repair. The impact caused a fractured fuselage, detached aft fuselage components, collapsed landing gear, and damage to the left wing and propellers.
The investigation
Investigators examined the aircraft and the pilot's performance calculations. The takeoff weight was 1,603 kg with the center of gravity positioned in the middle of the flight range. The pilot's calculations, which accounted for a 2.6% upslope, suggested a still-air takeoff distance required that would leave approximately 20 m of runway remaining.
A survey by the manufacturer's UK representative found no technical defects in the elevator control runs or the right engine Electronic Control Unit. While the left engine ECU could not be inspected due to accident damage, no operational or technical deficiencies were identified in the aircraft's systems. The pilot noted that while he had previously operated the aircraft from this runway at higher weights, he could not identify a specific cause for the lack of rotation, though he suggested local wind effects might have played a role.
Findings
- The pilot was unable to achieve rotation despite reaching the planned rotation speed.
- The aircraft failed to rotate during the takeoff roll, leading to a runway excursion.
- The transition from asphalt to grass increased drag, preventing the aircraft from accelerating further during the aborted takeoff.
- No technical or mechanical failures were identified in the aircraft's flight controls or engines.