A-5 open-class glider circa 1923.

By Alexander Belov , http://abelov.www2.50megs.com/planer/soar.html

The first open-class record-setting glider designed and built in Soviet
Union. First flown in 1923. Participate in 1-st and 2-nd all-Union glider
competitions. In 1923, piloted by Jungmeister, set the first Soviet record
of soaring flight durability: 1 hour 2 minutes and 30 seconds.