|FIGHTER||Virtual Aircraft Museum / USSR / Russia / Yakovlev|
During the autumn of 1946, the Yakovlev OKB initiated a relatively modest redesign of the Yak-15 which was initially referred to as the Yak-15U - Uluchshennyi (improved). The prototype, flown early in 1947, differed from its progenitor essentially in having a nosewheel rather than tailwheel undercarriage. Owing to the position of the engine, it was physically impossible to retract the nosewheel completely, and this was therefore partly enclosed by a fixed fairing. Introduction of a nosewheel demanded transfer of the main undercarriage members from the forward to the rear wing spar and dictated considerable structural redesign and a reduction in wing tankage. To compensate for the latter, a jettisonable 300-litre tank was added beneath each wing tip. Redesignated Yak-17, this fighter was restressed throughout and, in series form, was fitted with a redesigned vertical tail and an RD-10A engine rated at 1000kg. Armament remained two 23mm NS-23 cannon. Production of the Yak-17 followed on from the Yak-15 in late 1947, and continued for a year, a total of 430 being built, including a proportion of tandem two-seat Yak-17UTI conversion trainers. The Yak-17UTI entered flight test in April 1948, and about 150 were eventually built, 20 of these being exported to Poland and several to China. One Yak-17 fighter was delivered to Czechoslovakia for evaluation, where it received the designation S 100, and three were supplied to Poland. The latter country acquired manufacturing licences in 1950 for both the Yak-17 and its RD-10A turbojet, which were to be built at Mielec and Rzeszow respectively. The Polish programme was terminated in the winter of 1950-51 before any aircraft had been built as the Yak-17 had been overtaken by more efficacious fighters, but 30 RD-10 A engines were completed at Rzeszow. The Yak-17 and Yak-17UTI were phased out by the V-VS in 1951 and 1953 respectively, and the latter from the Polish air arm by 1955.