What happened
On 6 November 2006, a Cirrus SR22, registration N588CD, was conducting a training flight at Chichester (Goodwood) Airfield in West Sussex. The flight was part of a course for a student pilot to obtain an AOPA Flying Companion’s Certificate, with an instructor present in the left seat.
During the takeoff roll on Runway 24, the student pilot experienced difficulty maintaining directional control due to the aircraft's tendency to veer left under power. As the aircraft reached approximately 60 kt, the instructor instructed the student to initiate rotation. However, the student, feeling distracted and alarmed by the aircraft's lateral movement, mistakenly used her left hand to pull back on the throttle lever instead of the control stick. This action inadvertently closed the engine power.
Upon noticing the power reduction, the instructor took control and attempted to abort the takeoff. The instructor applied the brakes, but the aircraft failed to decelerate effectively due to the wet grass surface. The aircraft continued down the runway, eventually crossing the intersection of the active runway and striking a tyre barrier at an estimated speed of 10 to 20 kt. There were no injuries to the two crew members on board.
The investigation
The AAIB examined the sequence of events, the aircraft's performance capabilities, and the airfield conditions. The investigation noted that the aircraft was well below its maximum takeoff weight. While the aircraft's performance figures for dry grass suggested a successful stop was possible, the investigation focused on the impact of the wet grass surface.
An eyewitness, the airfield's flight information service officer, observed the aircraft's acceleration and noted a reduction in engine power. The investigation also considered whether recent grass cuttings on the runway contributed to the lack of braking action. Following consultation with the CAA’s Aerodrome Standards Department, it was determined that the grass cuttings were too small to have significantly impacted the braking performance.
Findings
- The student pilot's inadvertent closing of the throttle caused a significant loss of engine power during the takeoff roll.
- The student pilot was distracted by the difficulty of maintaining directional control with the rudder pedals.
- The wet grass surface reduced the effectiveness of the aircraft's braking action.
- The instructor's decision to abort the takeoff was necessitated by the decaying airspeed following the power reduction.