1936 Polikarpov R-5 modified to accept paratroopers.
https://diqn32j8nouaz.cloudfront.net/polikarpov_r5.jpg
More: https://en.wikipedia.org/wiki/Polikarpov_R-5
Previously:
https://www.homemadetools.net/forum/...618#post128427
https://www.homemadetools.net/forum/...111#post100764
https://www.homemadetools.net/forum/...2642#post76720
