IS-4 Jastrząb - the fastest glider, too fast for the air [Vintage Sky]
Channel: Zabytki Nieba - Vintage Sky
Date: 2018-02-23

Learn how fast can you go without an engine, and what does "siekiera" mean...
Polish version: https://www.youtube.com/watch?v=R_9hZKw3BBs
Twitter: https://twitter.com/Zabytki_Nieba
P.S: this is my first movie, and due to microphone failure the sound is in most cases only in the right channel.