This type resulted from an October 1946 requirement, and as one of the bureau’s first all-metal stressed-skin designs was based on a “stepped” fuselage with the RD-500 engine (in essence a British unit, the Rolls-Royce Derwent V centrifugal-flow turbojet, built in the USSR) located in the forward fuselage and exhausting below the fuselage in line with the cockpit and trailing edges of the unswept wing. This kept the engine installation as short as possible, and so avoided the efficiency losses associated with a long jetpipe. The Yak-23 possessed wing and horizontal tail surfaces similar to those of the Yak-19, and was intended to fulfil a requirement for a lightweight day interceptor capable of operating from existing fields.
The first of three prototypes of the Yak-23, which were of all-metal stressed-skin construction and powered by imported Rolls-Royce Derwent turbojets, was flown on 17 June 1947. Seen as something of a back-up for the very much more advanced Nene-engined fighters with wing sweep-back then under development, the Yak-23 proved itself an outstandingly agile warplane. NATO code name Flora.
Manufacturer's trials were completed on 12 September 1947. State Acceptance testing had been successfully completed before the year's end and series production began in the late spring of 1948.
The series Yak-23 was powered by a Soviet copy of the Derwent known as the RD-500 - a designation derived from GAZ-500, the factory in which the engine was produced - and rated at 1590kg. Its armament consisted of two 23mm NS-23 (later NR-23) cannon.
Deliveries to the V-VS began early in 1949, by which time the first production examples of the MiG-15 had already flown. In consequence, only two V-VS regiments reportedly re-equipped (from the Yak-17) with the Yak-23, which was quickly released for export. Twelve were delivered to Czechoslovakia during 1950 (and there assigned the designation S101) and the supply of some 95 to Poland began late that year, while, in 1951, 12 each were delivered to Romania and Bulgaria. Both Czechoslovakia and Poland were to have licence-built the Yak-23 but, in the event, manufactured the MiG-15, and Soviet production of the Yakolev type terminated in 1950 with 310 built.
One example was converted by the OKB as a tandem two-seat conversion trainer (Yak-23UTI), this first being flown in the spring of 1949. One Yak-23 was rebuilt as a tandem two-seater in Romania, but the type had given place to the MiG-15 in all Warsaw Pact air forces by the mid '50s.
Principal versions - Yak-23 (basic fighter model) and Yak-23UTI (two -seat conversion trainer whose production is unconfirmed). Principal users - Czechoslovakia, Poland, Romania, USSR, and possibly other Warsaw Pact countries.
Engine: one 3,505-lb (1,590-kg) thrust RD-500 turbojet
Wing span 28 ft 7.75 in (8.37 m)
Length 26 ft 7.75 in (8.12 m)
Wing area 145.32 sq ft (13.50 sq.m)
Height: 10.827 ft / 3.31 m
Empty weight 4,409 lb (2,000 kg)
Maximum take-off weight 7,460 lb (3,384 kg)
Maximum speed 606 mph (975 kph)
Initial climb rate 9,252 ft (2,820 m) per minute
Service ceiling 48,555 ft (14,800 m)
Range 746 miles (1,200 km)
Armament: two 23-mm cannon
Bombload two 132-lb (60-kg)