Yakovlev Yak-38

Yak-38

Picture - A Yak-38 on the deck of a Soviet aircraft carrier

Role: VTOL fighter
National origin: Soviet Union
Manufacturer: Yakovlev
First flight: 1971
Introduced: 1976
Status: Retired
Primary user: Soviet Navy
Number built: 231
Unit cost: US$18.5 million in 1996
Developed from: Yakovlev Yak-36

The Yakovlev Yak-38 (Russian: Як-38, NATO reporting name: Forger) was Soviet Naval Aviation's first and only operational VTOL strike fighter aircraft.

Design and development

The first drawings showed a supersonic aircraft strongly resembling by the Hawker P.1154 in study in the United Kingdom but with two R27-300 engines. Supersonic performances would have implied many difficulties of development, and it was decided to initially develop a relatively simple aircraft limited to Mach 0.95. Although the Yak-38 and Yak-38M were developed from the land-based Yakovlev Yak-36, the aircraft had almost nothing in common.

The Prototype VM-01 was finished on April 14, 1970. Though outwardly similar to the British Harrier Jump Jet, it followed a completely different configuration. Apart from having a vectorable engine in the rear used for flight, two smaller, less powerful engines were housed in the front portion of the aircraft and used purely for take-off and landing. (The Harrier uses only one engine, vectoring its thrust through four nozzles.) The aircraft used a similar layout to the German experimental VTOL strike fighter, the VFW VAK 191B, which began development in 1961, and the contemporary Dassault Mirage IIIV.

Picture - A diagram showing the lift forces on a Yak-38 in VTOL mode

The Yak 36 was sent for tests in May and June 1970. Mikhail Deksbakh carried out the first flight of the VM-02 in conventional mode on January 15, 1971. The VM-03 made its first flight in short takeoff mode on May 25, 1971. Sea trials aboard the aircraft carrier ("aviation cruiser") Kiev were observed in 1975. 231 Yak-38 aircraft were produced, including 38 two-seat trainers (Yak-38U). These were based on the four Kiev class aircraft carriers.

The Yak-38 used a hands-free landing system. The aircraft could negotiate a telemetry/telecommand link with a computer system in the aircraft carrier which would allow it to be guided onto the deck with no interaction from the pilot.

Markings

The initial colour scheme worn by the AV-MF Yak-38 consisted of dark green anti-corrosion paint on the undersides of the aircraft, with dark blue upper surfaces. This was later replaced by a light grey over dark grey scheme, frequently associated with the Yak-38M. An unusual green-over-silver "tiger" camouflage scheme, reportedly seen on an aircraft onboard Leningrad in 1986, was probably applied for one cruise only. Special camouflage schemes may also have been applied to aircraft involved in the Romb-1 trials in Afghanistan in 1980.

Operational history

Picture - Yak-38 (cn 0201) at Museum of Technics, Moscow Region

The majority of Yak-36M initial production deliveries were to the 279 OKShAP (Otdelnyi Korabelnyi Shturmovoi Aviatsionnyi Polk, Independent Shipboard Attack Air Regiment) initially based at Saki, the AV-MF’s training centre in Crimea. Pilots for this unit were drawn from the Yakovlev OKB and the LII at Zhukovskii, as well as from the AV-MF. Established as early as December 1973, the 279 OKShAP of the Black Sea Fleet made use of a dummy Kiev class aircraft carrier deck, and also operated a pair of MiG-21UMs (and, briefly, Ka-25s) for training. The first AV-MF squadron embarked on Kiev in July 1976. On the conclusion of acceptance tests for the Yak-36M initial series in August 1976 (Kiev was underway in the Atlantic at this point), the aircraft was formally accepted by the AV-MF in October, under the new designation Yak-38.

Picture - Yak-38 (cn 0201)

On its arrival in Murmansk, the 279 OKShAP was transferred to the Northern Fleet, with subsequent flying operations mainly being conducted from Severomorsk-3. The 299 IIAP (Issledovatlesko-Instruktorskiy Aviatsionnyi Polk, Research and Instructor Air Regiment) had been formed as a training unit at Saki in September 1976 to replace the previous unit within the Black Sea Fleet.

The February 1978 entry into service of Minsk, the second Kiev class ship, was accompanied by a further series of Yak-38 shipboard trials, beginning in April 1978, and with the emphasis now placed on developing procedure for STOL operations. The passage of Minsk out of the Black Sea in February 1979 was duly followed by a major exercise involving the first two ships of the Project 1143 class in the Mediterranean. On this occasion, five aircraft from each vessel conducted formation exercises in proximity to NATO observers.

The Yak-38’s limited useful payload was always its Achilles’ heel, but the high ambient temperatures that had been encountered in the Black Sea during the summer 1976 trials frequently prevented the aircraft from carrying any external stores at all, despite a reduced fuel load. Similar problems were then encountered when Minsk sailed off the coast of West Africa and then in the Indian Ocean; in these instances the lift jets proved unwilling to start under hot and humid conditions. (An oxygen-boosting intake system helped alleviate the problem, and was installed from September 1979 during routine overhauls.) In July 1979, Minsk arrived in the Sea of Japan, where the vessel was home-ported at Strelok Bay, the Yak-38 component of its air wing thereafter being provided by the 311 OKShAP subordinate to the Pacific Fleet. The 311 OKShAP was the second AV-MF Yak-38 unit, and had been established in March 1976.

During its first few years of ship-borne operations the Yak-38 was not cleared to make rolling take-offs and run-on landings, leading some Western observers to believe that the fundamentals of its propulsion design restricted the type to VTOL operations. In fact, shipboard short take-off trials had begun by December 1979, while experiments with run-on landings followed onboard Minsk between September 1980 and February 1981. V/STOL operations were made easier by the addition of a refined automatic flight-control system, linked to a thumb switch on the pilot’s stick. Rolling take-offs were conducted with the lift engines deflected aft, the main engine nozzles being rotated automatically from 60° to 25° during the take-off run, before being slowly returned to the horizontal as the lift engines were shut down.

The Kiev class ships normally embarked a total of 12 single-seat Yak-38s, supplemented by two or three two-seat Yak-38Us, as part of an independent aviation regiment that also included two squadrons of (mainly anti-submarine warfare) helicopters. Of the seven landing pads available on the deck of each of the Project 1143s, all but one could accommodate the Yak-38.

During April and May 1980 four Yak-38s and four AV-MF pilots were deployed to Afghanistan as part of a 50-day trial codenamed Romb-1, although the ‘hot and high’ conditions prevented any meaningful combat missions from being undertaken - in total, 12 combat sorties were made, but only two 100 kg (220 lb) bombs could be carried. In the event, any involvement would have been further limited by the ‘near-operational’ nature of the Romb-1 deployment (which also involved the first and third prototype Su-25s). The aircraft involved were not intended to be subject to combat, but rather tested under conditions that simulated the battlefield to a high degree. Despite their official non-operational nature, aircraft involved in the Romb trials could be requested to undertake combat sorties by local divisional commanders, on an ad hoc basis. The Yak-38s and prototype Su-25s operated out of a specially prepared air base near Shindand. Even with a much-reduced fuel and weapons load, the Yak-38 proved incapable of operating during the hot daylight hours (after around 0500 hrs).

In September 1982, Novorossiysk - the third Kiev class vessel - was commissioned. By now the V/STOL technique had been well practised, and the resulting increase in the Yak-38’s overall performance and capability was exploited during the passage of Novorossiysk from Severomorsk to join the Pacific Fleet. In a maritime context, the Yak-38 was not limited to the decks of the Kiev class. In September 1983, AV-MF pilots operated from the civilian ‘Ro-Ro’ vessel Agostinio Neto, and NII-VVS pilots conducted further tests from another ‘Ro-Ro’, Nikolai Cherkasov. In both cases, use was made of a heat-resistant landing platform; further land-based trials tested the practicality of dispersed landing platforms, in a similar concept to the RAF’s Harrier operations in West Germany.

Variants

Picture - A Soviet Yak-38 Forger with its landing gear down

Yak-36M "Forger"

The initial pre-production version, differing slightly from the Yak-38. It weighed only 6,650 kg (14,660 lb) compared to the Yak-38's 7,370 kg (16,250 lb) and the engines were slightly less powerful.

Yak-38 "Forger-A"

The Yak-38 was the first production model, it first flew on January 15, 1971, and entered service with the Soviet Naval Aviation on August 11, 1976. A total of 143 Yak-38s were produced.

Yak-38M "Forger-A"

The Yak-38M was an upgraded version of the Yak-38, the main difference being the new Tumansky R-28V-300 and two Rybinsk RD-38 engines. The maximum take off weight in VTOL was increased from 10 x— 300 kg (660 lb) to 11 x— 300 kg (660 lb) (or 12,000 kg/26,450 lb in short takeoff mode). The air intakes were slightly widened and the pylons under wings were reinforced to carry a ton of armament. Yak-38M begin entered service with the Soviet Naval Aviation after June 1985, a total of 50 Yak-38M were produced.

Yak-38U "Forger-B"

Two-seat training version for the Soviet Naval Aviation, this version differed from the basic aircraft in having an enlarged fuselage to accommodate a two-seater cockpit. The Yak-38U entered service on November 15, 1978, a total of 38 Yak-38U have been produced with the 38th aircraft being delivered in 1981.

Unbuilt projects

Yak-36P (or Yak-36MF)

Intended supersonic follow-on to the attack-optimised Yak-36M, adding AI radar, medium-range AAMs and advanced navigation equipment. A third RD-36-35 lift jet was also added to cope with increased take-off weight.

Yak-36-70F

1970 project for supersonic light fighter with a pair of afterburning (hence ‘F’ suffix) lift/cruise engines, lift engines deleted, variable intakes, bicycle undercarriage.

Yak-36A

Project for version with R-49V lift/cruise engine and two lift engines; one fuselage completed for tests under Tu-16.

Yak-36O

Refined version of Yak-36M with 15,000 kgf (33,100 lbf) thrust Type 55 (or subsequently R-61V) engine in redesigned fuselage.

Yak-38L (Yak-38I?)

AL-21F lift/cruise engine replacing R-27V-300.

Yak-38MP

Yak-38M fitted with a weapons system derived from that of the MiG-29 and including N019 radar and advanced nav/attack suite.

Yak-39

Multi-role fighter/attack aircraft project dating from 1983, employing one R-28V-300 and two RD-48 engines, PRNK-39 avionics kompleks; S-41D multi-mode radar, larger wing, increased fuel capacity and expanded weapons options based around Shkval or Kaira PGM designation systems.

Operators

Soviet Union

Soviet Navy - Soviet Naval Aviation

Specifications (Yakovlev Yak-38M)

General characteristics

Crew: One
Length: 16.37 m (50 ft 1 in)
Wingspan: 7.32 m (24 ft 0 in)
Height: 4.25 m (14 ft 5 in)
Wing area: 18.5 m² (199 ft²)
Empty weight: 7,385 kg (16,281 lb)
Loaded weight: kg (lb)
Max takeoff weight: 11,300 kg (28,700 lb)

Powerplant: 1 x Tumansky R-28 V-300 turbojet, 66.7 kN (15,000 lbf)

Powerplant: 2x— Rybinsk RD-38 turbojets, 31.9 kN (7,870 lbf;) each

Performance

Maximum speed: 1 280 km/h (795 mph)
Range: 1,300 km (807 miles)
Service ceiling: 11,000 m (36,089 ft)
Rate of climb: 4,500 m/min (14,760 ft/min)
Wing loading: kg/m² (lb/ft²)
Thrust/weight: 1+

Armament

Guns: GSh-23L 23mm gun pod (GP-9). This gun could be carried in one or two PUK-23-250 pods fixed under the external pylons of wings.
Bombs: two FAB-500 or four FAB-250 under pylons, two incendiary ZB-500, or two nuclear tactical RN-28.
Rockets: various types of rockets (up to 240 mm).
Missiles: two anti-ship or air-to-surface Kh-23. Each missile weighed 285 kg, was radiocontrolled and had 10 kilometres of range. The Kh-23 requires a guidance pod on one of the pylons. R-60 or R-60M air-to-air missiles could be carried under the external pylons.
Other: external tanks.

Related development

Yakovlev Yak-36

Comparable aircraft

Harrier Jump Jet series
VFW VAK 191B
Yakovlev Yak-141

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Source: WikiPedia