What happened
On 24 September 2023, a Robin DR300-140, registration F-BSPK, was performing an introductory flight at Calais-Marck airport. The flight, which included a pilot and three passengers, was part of a local community event. After completing a local circuit, the aircraft was on its base leg for runway 24 at an altitude of approximately 790 ft when it struck kite tether lines.
As the aircraft transitioned from the base leg to the final approach, the pilot noticed the airspeed indicator progressively decreasing until the reading reached zero. The pilot followed established failure procedures and successfully landed the aircraft without further incident. Upon inspection on the apron, the pilot discovered that the leading edges of both wings had been sliced, and the pitot tube line had been severed.
The investigation
The investigation established that the aircraft collided with lines used for kite fighting, an activity involving high-tension tethers coated with abrasive materials like silicon carbide and alumina to cut opposing lines. A 69-meter section of this line was found embedded in the left wing.
Investigators determined that the kite system, which included a kite and a metal bar, had a total mass of approximately 780 g. Because this mass was under 1 kg, the activity fell outside specific European drone and tethered aircraft regulations. Furthermore, local authorities confirmed that no prior authorization had been requested for kite flying activities in the area on the day of the accident.
Findings
- The primary cause of the incident was the collision with kite tether lines used during unauthorized kite fighting maneuvers.
- The abrasive coating on the lines caused significant structural damage to the wing leading edges and the aircraft spar.
- The impact severed the pitot tube line, resulting in the loss of airspeed indications.
- The pilot was unaware of the collision at the time it occurred because no significant jolts or cockpit warnings were triggered.
- The kite flying activity was being conducted without local administrative notification or oversight.