What happened
On June 2, 2018, a Bombardier BD700 1A10 GLEX, registered as 9H-CIO, departed from Bern-Belp Airport (LSZB) for a flight to Antalya. During the initial climb phase, while the aircraft was at an altitude of approximately 4,000 ft over the city of Bern, the crew observed a Remotely Piloted Aircraft System (RPAS) in close proximity to their flight path.
The aircraft was climbing at a speed between 160 and 170 knots with the landing gear retracted and the autopilot engaged. The crew described the drone as a grey, rectangular object equipped with white lights. The drone was estimated to be positioned roughly 150 meters to the right of the aircraft's trajectory and approximately 30 meters below it. Following the encounter, the crew immediately notified the Bern air traffic controller and continued the flight without further incident. There were no injuries to the crew and no damage to the aircraft.
The investigation
The investigation examined flight data from 9H-CIO and compared it against authorized drone activities in the area. At the time of the incident, a Notice to Airmen (NOTAM) was active for the airspace north of the Inselspital hospital, authorizing specific drone test flights for the Swiss Post AG. These authorized flights were restricted to a maximum altitude of 500 ft above ground level.
Analysis of the flight tracks revealed that the two drones involved in the authorized testing were located approximately 2 km northwest of the business jet's position at the time of the near-miss. Consequently, the investigation concluded that the drones involved in the official testing were not responsible for the encounter.
Findings
- The encounter was caused by an unidentified, unauthorized drone operating in the vicinity of the aircraft's flight path.
- The authorized drone operations in the area were operating at a much lower altitude and a different geographic location than the point of the near-miss.
- Because drones are primarily visible only to the naked eye and are not typically detected by aircraft collision warning systems, there is a significant risk of future mid-air collisions.