IFR go-around into glider zone triggers airprox with aerobatic ASK 21

An IFR Piper PA-28RT Arrow flew a training go-around at Grenchen and strayed into active glider restricted area LS-R 83, where a Schleicher ASK 21 was flying aerobatics; the two came within 80 m horizontally and 190 m vertically. Neither was damaged and no one was hurt. The Arrow was inbound IFR from Les Eplatures; its crew did not see the glider, while the glider instructor saw the Piper and reported it to the tower. The restricted area sat inside the active Class D zone, but the small lateral gap between the IFR go-around path and the glider area was barely discernible on the IFR displays.

1. Aerobatics in glider box: The Schleicher ASK 21 was flying aerobatics in active glider restricted area LS-R 83, south of Grenchen.
2. IFR go-around strays in: During a training go-around, the IFR Piper Arrow unintentionally entered restricted area LS-R 83.
3. Areas barely separated: The IFR go-around path lay so close to LS-R 83 that the encroachment was hard to detect on the IFR navigation displays.
4. Instructor sees and reports: The glider instructor saw the approaching Piper and reported it to the tower; the Arrow crew did not see the glider.
5. 80 m / 190 m separation: Closest approach was about 80 m horizontal and 190 m vertical; no contact and no injuries. Airprox category B2.