B737-800 climbs to avoid unseen glider on IFR descent

A Boeing 737-800 on an IFR flight from Antalya to Nuremberg came within an estimated 100-150 m horizontally and 45-60 m vertically of an unidentified glider in Class E airspace; the Boeing landed safely. Descending through about 1,830 m MSL the crew sighted the glider slightly left of track, in a right turn and apparently climbing, about ten seconds before reacting. The PIC disconnected the autopilot, altered heading from 300 to 308 degrees and stopped the descent at about 1,890 m MSL; the glider passed beneath the Boeing's left wing. The glider had no transponder and could not be identified on civilian radar or TCAS.

1. IFR descent toward Nuremberg: A Boeing 737-800 was on an IFR flight from Antalya to Nuremberg with 6 crew and 113 passengers, descending through Class E airspace toward 6,000 ft AMSL under sequential radar clearances.
2. Glider VFR without transponder: An unidentified glider was operating VFR in the same Class E airspace, climbing in a right turn; without an active transponder it appeared on neither ATC radar nor the Boeing's TCAS.
3. Crew spots glider ~10 s before action: About ten seconds before the avoidance manoeuvre the crew saw a climbing glider in a right turn slightly left of track; the PIC judged the current track would lead to a collision.
4. AP off, right turn, descent stopped: The PIC disconnected the autopilot and altered heading from 300° to 308° using the control wheel, reducing the sink rate and stopping the descent at about 6,200 ft AMSL.
5. Pass ~100-150 m horiz / 45-60 m vert: The glider passed beneath the Boeing's left wing; the PIC estimated the closest separation at 100-150 m horizontally and ~45-60 m vertically before the Boeing landed normally at Nuremberg.