PZL-105L Flaming

The improved variant of the Wrona bore the designation Wrona-bis. It differed from the original version primarily by an increased wingspan of 0.5 m and a reinforced structure. Wrona-bis gliders were built between 1934 and 1939 at Antoni Kocjan’s workshops, the Military Glider Workshops in Krakow, the Scout Glider Workshops in Warsaw, and by gliding clubs based on the documentation – approximately 400 examples in total. They were used for glider training at, among others, the famous Bieszczady glider schools – Bezmiechowa and Ustjanowa. Wrona-bis gliders were also built under license in Estonia, Finland, Bulgaria, Yugoslavia, and Palestine. In 1935, the renowned Polish glider pilot Piotr Mynarski made a soaring flight lasting 4 hours 7 minutes on a Wrona-bis.

In 1939, the Wrona-bis gliders, along with other Polish gliders, were seized at the gliding sites by the occupiers. Twelve examples of Wrona-bis gliders are known to have been transferred to Slovakia by the Germans. In 1942, Poles trained on Wronas in Palestine. One Palestinian Wrona has survived and is held at the Israel Air Force Museum in Hatzerim. In Poland, only one Wrona-bis survived, built at the Military Glider Workshops in Krakow. After the war, it was overhauled at the Gliding Institute in Bielsko-Biala, and was subsequently used for flight research. It is now exhibited at the Polish Aviation Museum with the postwar registration SP-127.