During the autumn of 1946, the Yakolev 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 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, 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.
The Yak-17 was powered by the uprated RD-10A rated at 1000 kg (2205 lb) of thrust. The NATO code named Feather was slightly faster and lighter than its competitor, the La-150, and was substantially superior in range; rough-field performance of the Yak-17 was very much better than that of the Lavochkin design, which had a heavy narrow-track undercar-riage. The La-150 was abandoned in April 1947 and the Yak-17 was ordered into pro-duction.
A second cockpit was added in front of the existing position and a long sliding canopy was fitted; an enlarged fin was also adopted for both the Magnet and Feather. 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. Poland 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 better 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.
Production of the Yak-17 from late 1947 to August 1949 and totalled 430, including a proportion of tandem two-seat Yak-17UTI conversion trainers. The Yak-17UTI was the Soviet air force's first specialist jet trainer and remained in service until replaced by the MiG-15UTI.
Engine: RD 10 A, 9810 N / 1000 kp
Max take-off weight: 3323 kg / 7326 lb
Empty weight: 2430 kg / 5357 lb
Wingspan: 9.20 m / 30 ft 2 in
Length: 8.78 m / 28 ft 10 in
Wing area: 14.85 sq.m / 159.84 sq ft
Height: 9.514 ft / 2.9 m
Max. speed: 750 km/h / 466 mph
Cruise speed: 600 km/h / 373 mph
Range: 717 km / 446 miles
Service ceiling: 42651 ft / 13000 m
Armament: 2x MK 23mm