What happened
On May 8, 2013, a paraglider pilot began a cross-country flight from the Jura mountains toward the Black Forest. At approximately 14:04 UTC, the pilot entered the LSZH 6 terminal area, a Class C controlled airspace, without authorization. The paraglider was flying at an altitude of approximately 5,502 feet AMSL, which was below the 5,500-foot floor of the controlled zone.
While navigating this airspace, the paraglider encountered four dangerous approaches with commercial aircraft on final approach to Zurich Airport. The third encounter involved an Airbus A319-112, registration HB-IPX, operating as flight SWR 63M. The aircraft and the paraglider passed with a horizontal separation of roughly 390 meters and a vertical separation of 100 meters. The flight crew of SWR 63M reported visual contact with the paraglider.
Approximately eight minutes later, a second near-collision occurred with an AVRO 146-RJ100, registration HB-IYS, operating as flight SWR 78W. This encounter was significantly closer, with the aircraft passing the paraglider at a horizontal distance of only 160 meters and a vertical separation of just 14 meters. The crew of SWR 78W also reported seeing the paraglider and provided its position to air traffic services.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) examined the flight paths, radar recordings, and communication logs. The investigation focused on why the paraglider was able to penetrate the controlled airspace undetected by radar and why the aircraft's onboard safety systems failed to provide warnings.
Findings
- The paraglider entered Class C airspace without the required authorization.
- The paraglider lacked a transponder, which meant it was invisible to radar and could not be detected by the Air Traffic Controller.
- Because the paraglider had no transponder, the Traffic Collision Avoidance Systems (TCAS) on both the Airbus A319-112 and the AVRO 146-RJ100 were unable to generate traffic advisories or resolution advisories.
- The paraglider pilot failed to heed a airspace warning displayed on their GPS device.
- The pilot did not take corrective action after the first near-miss with a commercial aircraft.
- The pilot's preparation for the cross-country flight was insufficient.
Safety action
To address the systemic risk of non-transponder equipped aircraft in controlled airspace, the SUST has recommended the creation of specific airspaces around Swiss airports where only aircraft equipped with functional transponders are permitted to operate.