The Yakovlev Yak-23, a Soviet jet fighter equipped with a straight wing, emerged as a successor to the Yak-17 during the late 1940s.
Notably, it incorporated a reverse-engineered replica of a British engine.
However, due to its inferior performance compared to the swept-wing Mikoyan-Gurevich MiG-15, the Yak-23 did not witness extensive production.
Despite this, numerous Yak-23s were exported to nations within the Warsaw Pact and continued to serve throughout the majority of the 1950s.
Remarkably, a few of these aircraft remained operational even a decade later.
On 11th of March 1947, the Council of People’s Commissars issued a directive to various design bureaux (OKB), including the one led by Alexander Yakovlev, to undertake the development of a solitary-seated, straight-winged jet fighter.
This aircraft was intended to be equipped with either a single British Rolls-Royce Nene or Rolls-Royce Derwent turbojet engine.
The specified performance requirements for this fighter entailed achieving a maximum speed of 950 kilometers per hour (590 mph) at sea level, and a speed of 1,000 km/h (621 mph) at an altitude of 5,000 meters (16,400 ft).
Additionally, it was expected to ascend to this altitude within a timeframe of 3.5 minutes or less, while possessing a maximum range of no less than 1,200 kilometers (750 mi).
In response to the Ministry’s directive, Alexander Yakovlev opted to pursue the development of two distinct designs.
The first was the Yakovlev Yak-25, which adhered to the Ministry’s specifications, while the second was a lightweight and more maneuverable aircraft known as the Yak-23.
Yakovlev’s decision to pursue both designs was not without risk, as it could potentially be perceived as an unauthorized utilization of state funds if discovered.
Such a discovery could have subjected Yakovlev to significant repercussions.
In order to reduce risk, the Yak-23 fighter aircraft utilized the same “pod-and-boom” layout as its predecessor, the Yak-17.
However, the metal fuselage was redesigned to incorporate a semi-monocoque structure, with the cockpit positioned just above the trailing edge of the wing and featuring a teardrop-shaped canopy.
This placement was not coincidental, as it was directly above the exhaust of the Klimov RD-500 engine, which was an unlicensed copy of the Derwent V and produced 1,590-kilogram-force (15.6 kN; 3,500 lbf) of centrifugal-flow.
The Yak-23 also featured tricycle landing gear, with the main landing gear retracting inwards into the fuselage and the nose gear retracting forwards.
Unlike the Yak-17, the Yak-23’s forward landing gear was flush with the fuselage when retracted.
The wing, which was mounted in the middle of the fuselage, was a laminar-flow, two-spar design with slotted flaps and ailerons and a modest 3° 30′ dihedral.
The horizontal stabilizers had 5° of dihedral.
The pilot was protected by a bulletproof windscreen and an armored ejection seat.
The Yak-23 was equipped with five non-self-sealing fuel tanks in the fuselage, with a total capacity of 910 liters (200 imp gal; 240 U.S. gal) of fuel.
Additionally, it could carry a pair of 195-liter (43 imp gal; 52 U.S. gal) drop tanks under the wingtips.
The fighter was armed with two 23-millimeter (0.9 in) Nudelman-Rikhter NR-23 autocannon, each with 90 rounds.
Two prototypes and a static-test airframe were commissioned, and the aircraft made its inaugural flight on 8 July 1947 under the command of Lieutenant Colonel Mikhail Ivanov, the esteemed Hero of the Soviet Union.
While still engaged in the manufacturer’s flight testing, the first prototype partook in the flypast at Tushino Airfield on 3 August.
The Yakovlev OKB concluded its testing on 24 September and subsequently handed over the second prototype for state acceptance trials on 22 October.
Despite being approved for mass production, the Yak-23 faced criticism for its heavy aileron and rudder forces, absence of cockpit pressurization and inadequate heating and ventilation systems, insufficient pilot protection, and weak armament.
Nonetheless, test pilots lauded its exceptional maneuverability, commendable acceleration, and impressive takeoff and climb capabilities, all attributed to its favorable thrust-to-weight ratio.
Subsequently, the second prototype underwent modifications to address these concerns and underwent successful retesting in 1948.
In October 1949, the first aircraft were manufactured in a factory located in Tbilisi.
These aircraft were later introduced into the Soviet air force service towards the end of the same year.
However, the Yak-23 was soon replaced by the more complex swept-wing MiG-15, which offered better performance.
Production of the Yak-23 ceased in 1951, with only 316 units being built.
In addition to the fighter version, two trainer versions of the Yak-23 were also produced, albeit in small numbers.
These were the Yak-23UTI two-seat trainer, which had an unusual arrangement of the instructor sitting in front of the student, and the Yak-23DC trainer, which was manufactured in Romania.
A few Yak-23s were exported to other countries, including Czechoslovakia (20 units from 1949, named S-101), Bulgaria (from 1949), Poland (about 100 units from 1950), and Romania (62 units from 1951).
Although Poland and Czechoslovakia acquired licenses for the aircraft, they opted to build the superior MiG-15 instead.
By the late 1950s, Yak-23s had been phased out, except in Romania where they were still in use until 1960. Variants Yak-23 Fighter version, serial built. Yak-23UTI Two-seat training version with longer fuselage and lighter armament, three built. Yak-23DC Romanian-built two-seat training version. Four Yak-23 single-seaters were converted in 1956 by ASAM Pipera, two of them belonging to the Bulgarian AF. S-101 Czechoslovak designation. Specifications Yak-23 Crew 1 Length 8.13 m (26 ft 8 in) Wingspan 8.73 m (28 ft 8 in) Height 3.31 m (10 ft 10 in) Wing area 13.5 m2 (145 sq ft) Empty weight 1,980 kg (4,365 lb) Gross weight 3,384 kg (7,460 lb) Powerplant 1 × Klimov RD-500 centrifugal-flow turbojet engine, 15.6 kN (3,500 lbf) thrust Performance Maximum speed 925 km/h (575 mph, 499 kn) at sea level Range 1,200 km (750 mi, 650 nmi) Service ceiling 14,800 m (48,600 ft) Rate of climb 47 m/s (9,300 ft/min) Thrust/weight 0.46 Armament Guns 2 × 23 mm Nudelman-Rikhter NR-23 with 90 rpg Sources Yakovlev Aircraft Since 1924 – Bill Gunston & Yefim Gordon. OKB Yakovlev, A History of the Design Bureau and its Aircraft-Yefim Gordon, Dmitriy Komissarov & Sergey Komissarov. Soviet Aircrafts Illustrated-A.S.Yakovlev. The History of Soviet Aircraft from 1918-Vaclav Nemecek. Soviet AF Fighter Colours 1941-45-Erik Pilaeskii. Soviet Combat Aircraft of the Second World War, Vol 1, Single Engined Fighters-Yefim Gordon and Dmitri Khazanov. Early Soviet Jet Fighters, The1940s and early 50s-Yefim Gordon.
