What happened
On May 28, 2014, at approximately 20:55 local time, a Cessna 207A, registration LN-PER, was conducting a flight from Skien Airport Geiteryggen (ENSN) to transport six skydivers to a jump site. After departing runway 01 and climbing to 4,800 feet, the aircraft entered the Farris TMA, a controlled airspace class C.
While established on a southbound course approximately 5 nautical miles south of the airport, the pilot observed an unidentified drone approaching from the opposite direction. The drone, described as a black flying-wing design with fluorescent green markings on its rear, passed the aircraft on the left at nearly the same altitude. The pilot estimated the separation distance was no more than 50 meters. Following the close encounter, the pilot observed the drone perform a rapid, spiral-like descent before it disappeared from view.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the flight path, radar data, and testimonies from the pilot and the passengers. The investigation focused on the presence of the unmanned aircraft within controlled airspace and the operational nature of the drone. Because the drone's operator did not contact the NSIA, the exact weight and dimensions of the drone could not be determined.
Findings
While the NSIA concluded there was no immediate risk of a collision during the encounter, the incident was classified as a significant air traffic occurrence due to the unauthorized use of a drone within controlled airspace. The investigation established that:
- The drone was operating in a manner suggesting it may have been flown beyond visual line-of-sight (BVLOS), possibly utilizing a video link.
- The presence of an unidentified flying object in controlled airspace violates the expectation of predictable traffic, where aircraft are required to carry transponders and maintain two-way radio communication.
- The maneuver performed by the drone could have easily resulted in a direct collision course that the pilot might not have had sufficient time to avoid.
Safety action
The NSIA expressed concern regarding the rising frequency of conflicts between drones and manned aircraft. The authority emphasized that improved regulation through the Norwegian Civil Aviation Authority and the EASA framework is essential to manage the risks posed by unauthorized or unorganized drone operations, particularly those involving equipment capable of operating beyond the pilot's visual range.