Let C-11

10/31/2010. Since the Second World War almost all Soviet piston-engined training aircraft, apart from conversions of operational military aircraft, have been designed by the Yakovlev design bureau, and for many years were the standard trainers for all Communist air forces.

The first of these, the Yak-11, was clearly based on Yakovlev's successful wartime fighters - the form of the wings and tail unit was the same, and the undercarriage was similar to that of the Yak-1/Yak-3 series; only the two-seat fuselage with its radial engine was new. Yakovlev kept up his reputation for clean design by producing a close fitting, and unblemished, radial cowling which, like its in-line engined forebears had oil-cooler air intakes in the wing-roots.

The Yak-11 was flight tested in 1946 and deliveries to Soviet air force training units began in 1947. In March 1948 a Soviet pilot force-landed his Yak-11 in Turkey while on a delivery flight from the Yakovlev factory at Zaporozhe, so unintentionally enabling Western observers to have their first opportunity of examining the type. During the 1950s a number of class Id (3,858-6,614 lb/1,750-3,000 kg gross weight) records were established by Yak-11s flown by pilots of the Chkalov Central Aero Club, these records included:

The Yak-11 was a single-engined low-wing cantilever monoplane of all-metal construction with metal and fabric covering. The engine was a 730 hp Shvetsov ASh-21 seven-cylinder air-cooled radial engine. A VISh-III-DI5 two-blade constant-speed metal propeller and cooling fan were fitted. The undercarriage main units retracted inwards and the tailwheel was non-retractable. The Yak-11U introduced during 1956 had a retractable nose wheel undercarriage. Armament consisted of a single 0.30 in (7.62 mm) ShKAS machinegun in the engine cowling, while racks for practice bombs or rocket rails could be fitted beneath the wings.

Altogether, 3,859 Yak-11s were built in the USSR between 1946 and 1956, while an additional 707 aircraft were built under license between 1954 and 1956 by LET Kunovice and were designated C-11 and C-11U. The Yak-11 has been used by the air forces of 18 countries, including Afghanistan, Albania, Austria (four presented by the Soviet Government), Bulgaria, China, Czechoslovakia, Egypt, Hungary, Poland, Rumania, Syria, USSR, and Yemen.