The second floor of the museum was mostly exhibits on the history of flight in Serbia and Yugoslavia.
Normally I like to keep the photos going in a fairly linear fashion, but the unique design of this museum affords better views of the main planes, so I'll be bouncing back and forth a bit when the shot demands it.
The tiny, tiny, appropriately named Folland Gnat. Though sold in great numbers to other countries (including India), only two test examples came to Yugoslavia. One crashed. The YAF decided they were too expensive to manufacture and passed on a larger order.
Certainly one of the stranger aircraft I've ever seen, this is an Ikarus 451, part of a family of research aircraft. The pilot was in the prone position. This gave me a stiff neck just thinking about it.
Coaxial rotor helicopter! I've never seen one of these in person -- fascinating. Kamov is one of the only companies to make this type of helicopter in large numbers. The rotor hub needs be super-complex in order to ditch the tail rotor of "traditional" helicopters. This is a Ka-25.