In 1938, Germany threatened Czechoslovakia. For a variety of reasons, England and France backed down in the face of the threat of war with Germany, and allowed Germany to dismember Czechoslovakia and create the "rump" state of Slovakia, a puppet ally throughout World War 2. This was more of a feat than it seems - Germany was the 5th rated industrial power in the world, and Czechoslovakia was the 7th.
A significant number of German aircraft were used in Czechoslovakia as well (Bf 109G, Me 262, He 111, Ju 52, Bü 131, Bü 181, Ar 96, Fi 156, Fw 58, Fh 104, Si 204, He 219, Fa 223, etc.).
On 8th May 1945, one of the last victories attached the Luftwaffe happened abovethe Czech republic. That day about 4 PM Oblt. Fritz Stehle (I./JG 7) flew from the airport at Zatec and moved with his Messerschmitt Me 262A to the British sector in Germany (Fasseberg airfield). Above the Krusne Hory Mountains he shoot down Soviet Bell P-39Q Airacobra piloted by Lt. Sergej Griorjevic Stepanov from 129. GIAP. Soviet pilot (21 years of age) died. Oblt. Stehle surrendered after that to the British.
In 1945, the Czech pilots returned home with their Spitfires and Lavochkins used in the war. These machines became the standard fighters in the first post-war years. There were also some planes left behind by the Luftwaffe. New planes were delivered by Avia. During the war, the company produced Messerchmitts Bf-109 for the Reich. The natural thing to do was continue with this production. There were, however, no original engines for the Bf-109 in the country. That's why the engine was replaced by a heavier and more powerful type, which was plentiful. The plane was too nose heavy and the engine was overpowered for the design. The Avia designers did their best to improve the qualities of the plane, but this was only partly successful. The result was called Avia S-199, and its two-seater version was CS-199. The pilots called it "mezek" - a short form of Messerschmitt, but also the Czech expression for "the mule", due to its mule-like behavior. The plane was difficult to balance, and had a tendency to roll over during the landing (this was a problem even with the original Bf-109). If this happened, the engineers had to smash the cabin with a long pole to get the helpless pilot out. When the pilot revved up the engine during the take-off, the movement was so strong that the plane was in danger of hitting the ground with the wing. In spite of these problems, hundreds of S-199's were produced and used until 1955.
The moment of glory for S-199 came with the Israeli war of independence. Czechoslovakia was the only country ready to equip Israel with aircraft and train their pilots. A number of Spitfires and Avias were delivered to Israel. Israeli pilots learned to use the excessive engine moment for unexpected sharp turns in combat. According to some sources, if it hadn't been for Avias, there would be no Israel. It is ironic that the only Czech plane that played a decisive role in a real conflict was at the same time one of the worst Czech designs.
The communist coup of 1948 was an important turning point. From this time, Czechoslovak aviation became increasingly dependent on the Soviet Union, which had no interest in a prosperous Czechoslovakia. The superior light industry was suppressed and replaced by heavy industry. Aircraft manufacturers had to move to a different kind of production. Avia made licensed Soviet aircraft in the beginning, but starting from early 60s, aircraft production was stopped. Avia now makes trucks.