Unidentified glider triggers a near miss with an A320 in controlled airspace

An unidentified glider crossed the Zürich terminal control area at about 1800 m without contacting air traffic control or squawking a transponder, and passed close to an inbound Airbus A320 holding there; there was no collision and no injury. The airliner's crew saw the glider come out of a left turn and move away, about 90 m below and 700 m to one side. With the glider neither on the radio nor showing on radar, the controller could not separate it from the airliner. It was never identified — every glider flight from the nearby airfields was checked, and none of the pilots could have been involved.

1. Glider transiting controlled airspace: An unidentified glider was crossing the Zürich terminal control area (class C) at about 1800 m.
2. No radio, no transponder, no radar: The glider was not in contact with air traffic control and squawked no transponder code; it did not show on the controller's radar.
3. Controller cannot separate traffic: Unable to see or contact the glider, the controller could arrange no separation from an inbound airliner.
4. A320 crew sights the glider: An Airbus A320 holding at the same level saw the glider emerge from a left turn close by and move away.
5. Near miss, ~90 m below / 0.7 km: The crew passed the glider about 90 m below and 0.7 km to one side; there was no collision and no injury.