| Yak-23 | |
|---|---|
 Polish Yak-23 in theLubuskie Muzeum Wojskowe,Drzonów | |
| General information | |
| Type | Fighter aircraft |
| Manufacturer | Yakovlev |
| Primary users | Soviet Air Forces |
| Number built | 316 + 3prototypes |
| History | |
| Manufactured | October 1949–January 1951 |
| Introduction date | 1949 |
| First flight | 8 July 1947 |
| Retired | Early 1960s |
| Developed from | Yakovlev Yak-17 |
TheYakovlev Yak-23 (Russian:Яковлев Як-23;USAF/DoD reporting nameType 28,NATO reporting nameFlora)[1] is an earlySovietjetfighter with a straight wing. It was developed from theYak-17 in the late 1940s and used areverse-engineered copy of a British engine. It was not built in large numbers as it was inferior in performance to theswept-wingMikoyan-Gurevich MiG-15. Many Yak-23s were exported to theWarsaw Pact nations and remained in service for most of the 1950s, although some were still in use a decade later.
On 11 March 1947, theCouncil of People's Commissars ordered several design bureaux (OKB), including that ofAlexander Yakovlev, to develop a single-seat, straight-winged jet fighter to be equipped with a single BritishRolls-Royce Nene orRolls-Royce Derwentturbojet engine. The aircraft should have a maximum speed of 950 kilometers per hour (590 mph) atsea level and a speed of 1,000 km/h (621 mph) at an altitude of 5,000 meters (16,400 ft). It should be able to climb to that altitude in 3.5 minutes or less and should have a maximum range of no less than 1,200 kilometers (750 mi).Alexander Yakovlev decided to develop two designs, theYakovlev Yak-25 in accordance with the Ministry's order and a lightweight, more agile aircraft (the Yak-23) in the hopes that one or the other would win an order from the Ministry. Yakovlev's decision was a risky one as it could be construed as unauthorized use of state monies if discovered, which could have landed Yakovlev in a lot of trouble.[2]
To minimize risk, the new aircraft used the same "pod-and-boom" layout as the earlier Yak-17 fighter, but the metalfuselage was redesigned as a semi-monocoque structure with the single-seat,unpressurizedcockpit and its teardrop-shapedcanopy positioned just above the trailing edge of the wing. Not coincidentally, this was also above the exhaust of the 1,590-kilogram-force (15.6 kN; 3,500 lbf)centrifugal-flowKlimov RD-500 engine, an unlicensed copy of the Derwent V. Fitted withtricycle landing gear, the main landing gear retracted inwards into the fuselage while the nose gear retracted forwards. Unlike the installation in the Yak-17, the Yak-23's forward landing gear was flush with the fuselage when retracted. Thelaminar-flow, two-spar, wing was mounted in the middle of the fuselage. It was equipped withslotted flaps andailerons and had a modest 3° 30'dihedral. Thehorizontal stabilizers had 5° of dihedral. The pilot was protected by a bulletproof windscreen and the armored back of theejection seat. The Yak-23 was equipped with five non-self-sealing fuel tanks in the fuselage that had a total capacity of 910liters (200 imp gal; 240 U.S. gal) of fuel. In addition it could carry a pair of 195-liter (43 imp gal; 52 U.S. gal)drop tanks under thewingtips. The fighter was armed with two 23-millimeter (0.9 in)Nudelman-Rikhter NR-23autocannon, each with 90rounds.[3]
Twoprototypes and a static-testairframe were ordered and the aircraft first flew on 8 July 1947 with theHero of the Soviet Union,Lieutenant ColonelMikhail Ivanov, at the controls. While still involved in its manufacturer's flight testing, the first prototype participated in theflypast atTushino Airfield on 3 August. The Yakovlev OKB concluded its testing on 24 September and turned over the second prototype for state acceptance trials on 22 October. Although the Yak-23 was accepted for series production, it was criticized of heavy aileron and rudder forces, lack of cockpit pressurization and heating and ventilation, protection for the pilot and weak armament. The test pilots did praise it as highly maneuverable, with a good acceleration and takeoff and climb capabilities thanks to a high thrust-to-weight ratio. The second prototype was modified afterwards to address some of these issues and successfully tested again in 1948.[4]
The first aircraft were produced in a factory inTbilisi in October 1949. In late 1949 they enteredSoviet air force service. The Yak-23 was quickly replaced in the Soviet service with the more complicated swept-wing MiG-15, which offered superior performance. In all, only 316 Yak-23 aircraft were built before production ended in 1951. Apart from the fighter there were two trainer versions of the Yak-23 which were built in small numbers. TheYak-23UTI two-seattrainer which appears to have had the unusual arrangement of having the instructor seated in front of the student, and the Yak-23DC trainer which was produced in Romania.
Small numbers of Yak-23s were exported toCzechoslovakia (20 from 1949, namedS-101),Bulgaria (from 1949),Poland (about 100, from 1950),Romania (62, from 1951). Poland and Czechoslovakia acquired licenses for the aircraft, but built the superior MiG-15 instead. Yak-23s were withdrawn by the late 1950s, except in Romania which used them until 1960.[5]
A Romanian Yak-23 flown by Major Dumitru Balaur successfully intercepted a SovietIlyushin Il-28 on the night of 28 October 1952. Being tracked from the ground onradar, the Il-28 was intercepted by the Yak-23 fighter scrambled from theIanca airfield after it had passed into the Romanianairspace a second time. As the bomber refused to follow the Romanian pilot's instructions, the fighter moved into position to shoot it down but was recalled to base. This was the firstinterception mission carried out by the Romanian Air Force.[6]
A single Yak-23 was acquired by US intelligence viaYugoslavia in November 1953. The aircraft was a Romanian Yak-23 flown by Mihail Diaconu who had defected with it. The aircraft arrived disassembled and was shipped to the U.S. Air Force Test and Evaluation Center atWright Field nearDayton, Ohio.[7] It was reassembled and made operational for several test flights, during which time it was disguised with U.S. markings. Efforts were made to keep the aircraft's identity secret and it was flown only in the early morning. On one occasion it was passed on therunway by a formation ofF-86 Sabres whose pilots inquired as to the plane's identity. A story was conceived that the aircraft was aBell X-5, which had a similar layout. At the completion of design and flight evaluations the aircraft was again disassembled and shipped quietly back to Yugoslavia in its original paint scheme.
On September 21, 1957, the Polish pilotAndrzej Abłamowicz set twoFAI world records in the Yak-23 with civilian markings SP-GLK, in its weight class, climbing to 3,000 m (9,843 ft) in 119 seconds (4,962.6 ft/min, 25,21 m/s) and to 6,000 m (19,685 ft) in 197 seconds (5,995.4 ft/min, 30,45 m/s). This plane was withdrawn in 1961.
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Data from The Complete Book of Fighters[9]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Related lists
