What happened
On 10 April 2014, a FLS Aerospace Sprint 160, registration G-SCLX, was performing a training flight from a private grass airstrip in Kirdable, West Sussex. The flight was intended to prepare the pilot for a Licence Skills Test following a period of inactivity.
During the takeoff roll, the pilot utilized a two-stage flap setting to reduce the required ground distance. While the aircraft reached liftoff speed before the crest of the airfield's slope, it failed to establish a positive rate of climb. The aircraft's altitude decreased shortly after leaving the ground. As the aircraft approached the end of the strip, the pilot maintained a nose-high attitude to protect the propeller and cockpit. During this maneuver, the tail of the aircraft struck a wire fence located at the southern boundary of the field. The impact caused the left elevator to detach, and the aircraft eventually came to a halt in a field beyond the airstrip. There were no injuries to the two crew members on board.
The investigation
The AAIB examined the aircraft's performance and the airfield conditions. The investigation noted that the airstrip was approximately 400 meters long and featured a gradual upward slope for much of its length. Although the pilot had identified some soft patches during taxiing, the takeoff roll initially appeared normal.
Investigators looked into the aerodynamic implications of the aircraft's configuration. They specifically examined the transition from ground effect to free flight. While the pilot had successfully used high flap settings for takeoff previously, the investigation considered whether the increased induced drag at the moment the aircraft left ground effect exceeded the available engine power. Additionally, the investigation considered the possibility of a sudden tailwind component, despite calm surface conditions reported nearby.
Findings
- The aircraft entered a high-drag configuration by using an increased flap setting to minimize ground roll.
- The aircraft likely experienced a significant increase in induced drag when transitioning out of ground effect, which exceeded the power available to maintain a climb.
- The aircraft's tail struck a wire fence at the end of the airstrip, leading to damage to the tail surfaces and the detachment of the left elevator.