Cessna 172 climbs to avoid glider during IFR descent near cloud base

A Cessna 172 R on an IFR training flight came within an estimated 40-60 m of an unidentified glider near Bergheim (Germany); the Cessna landed safely. The Cessna was in IMC descending toward 915 m MSL with the instructor flying while the student configured the avionics. During a frequency change the student saw the glider through a cloud veil, slightly below and turning toward the Cessna from the left. The instructor terminated the descent, climbed and turned right, and levelled at about 1,280 m MSL once clear. The glider, marked with red tape on nose and wingtips, was flying without a transponder and could not be identified.

1. IFR training descent toward MGL: A Cessna 172 R flew an IFR training flight from Cologne-Bonn to Mönchengladbach, the instructor flying while the student configured avionics; cleared to 3,000 ft AMSL, heading north.
2. Cessna in IMC, glider below cloud: The Cessna was in instrument conditions during the descent, while the glider operated below the cloud layer in marginal visual conditions with cloud and haze.
3. Glider without transponder: The unidentified glider flew without an active transponder and did not appear on civilian radar. Military radar later showed a target close by, moving north-east; it went unidentified.
4. Student spots glider via cloud veil: During the frequency change the student noticed movement in his peripheral vision while entering nav data; through a cloud veil he saw a glider below, turning toward the Cessna.
5. Climb + right turn: The instructor terminated the descent, climbed in a right turn, and levelled off once the student reported clear of the glider, having seen red tape on its nose and later its wingtips.
6. Pass ~40-60 m, Cessna lands MGL: The Cessna pilot estimated the lateral separation at the closest point as about 40 to 60 m. There were no injuries and no damage. The Cessna landed normally at Mönchengladbach.