IFR ambulance jet and a circling JS1 pass close at an airspace boundary

An IFR ambulance jet approaching Zurich and a glider thermalling under VFR passed within about 1,060 m horizontally and 210 m vertically in Class E airspace, where IFR traffic is not separated from gliders; both crews saw each other and no one was hurt. Radar-vectored at 6,000 ft MSL, the jet was held 500 ft above the minimum vectoring altitude, which matched the floor of the airspace above and left no buffer. The glider was climbing just below that floor with no transponder, which was not required, so it never showed on radar and the jet's TCAS gave no alert. The two pilots relied on seeing each other in the clear air.

1. Glider thermalling in Class E (VFR): A glider on a VFR cross-country was climbing in a thermal over the Leibstadt area, in Class E just below the floor of the overlying controlled airspace.
2. No transponder; invisible to radar: The glider carried no transponder, which was not required; it never appeared on radar, so ATC could give no traffic information and the jet's TCAS could raise no alert.
3. Vectoring floor meets airspace floor: The jet was radar-vectored 500 ft above the minimum vectoring altitude, which coincided with the floor of the controlled airspace, leaving no vertical buffer at the boundary.
4. Jet and glider converge: On an IFR approach to Zurich at 6,000 ft MSL, the jet converged with the glider climbing just below at about 5,400 ft MSL; they closed to roughly 1,060 m horizontally and 210 m vertically, meeting at close to a right angle.
5. Both crews saw each other: In the good visibility each crew saw the other aircraft in time; the glider pilot had turned out of his thermal, and the jet crew reported the glider's position to the controller.
6. Passed clear, no injury: The jet continued its approach without an avoidance manoeuvre and the two aircraft passed clear; no one was hurt and neither aircraft was damaged.