The SZD-6X Nietoperz is a one-of-a-kind experimental tailless glider that was used to evaluate the utility of this type of configuration and to study a drag-based directional control system, i.e. without a vertical stabiliser, using outer ailerons that open like a crocodile’s jaws, serving as a rudder.
The glider was designed by Wladyslaw Nowakowski and Justyn Sandauer at the Gliding Institute in Bielsko-Biala, renamed the Glider Research Centre in 1950. The Nietoperz was first flown on 12 January 1951 in Bielsko-Biala by Adam Zientek.
The tow aircraft was another exhibit of the Polish Aviation Museum — a PWS-26 flown by Tadeusz Gora, the first Polish recipient of the Lilienthal Medal. Flight tests continued until 1959, after which the glider was transferred to the Museum of Technology in Warsaw. It was very difficult to fly and required special safety precautions during flight testing.
A similar drag-based control system, as tested on the Nietoperz, is used today in the American B-2 Spirit stealth bomber.
The Nietoperz was not the only experimental tailless glider. Three others were the IS-5 Kaczka, SZD-13 Wampir and SZD-20X Wampir 2.
