Sergey Ryabchinsky and Tilo Holighaus
Aleksandr Markin
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/33104187@N04/8734457337/">Schempp-Hirth Flugzeugbau. Sergey Ryabchinsky and Tilo Holighaus</a>