The Yakovlev Yak-141 (russian: Яковлев Як-141;
NATO reporting name
NATO reporting names are code names for military equipment from Russia, China, and historically, the Eastern Bloc (Soviet Union and other nations of the Warsaw Pact). They provide unambiguous and easily understood English words in a uniform manne ...
"Freestyle"), also known as the Yak-41, is a Soviet
supersonic
Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...
vertical takeoff/landing (VTOL)
fighter aircraft
Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...
designed by
Yakovlev
The JSC A.S. Yakovlev Design Bureau (russian: ОАО Опытно-конструкторское бюро им. А.С. Яковлева) is a Russian aircraft designer and manufacturer (design office prefix Yak). Its head office is in Aeroport D ...
. It was used for testing.
Design and development
Yakovlev always believed the
Yak-38
The Yakovlev Yak-38 (russian: Яковлев Як-38; NATO reporting name: "Forger") was the Soviet Naval Aviation's only operational VTOL strike fighter aircraft in addition to being its first operational carrier-based fixed-wing aircraft. It w ...
to be an interim aircraft, developed to gain experience designing and developing military VTOL aircraft. Even before the Yak-38's introduction, the Soviet Navy desired a more comprehensive aircraft, with greater capabilities than the Yak-38 offered. The result was a design contract offered to Yakovlev in 1975. The requirement was for an aircraft with only one mission: air defense of the fleet. Unlike the Yak-38, this aircraft was to have sustained supersonic speed. Maneuverability, radar and weapons loads were expected to be similar to those of current front-line fighters. For the Soviet Navy this aircraft was to be their next generation VTOL fighter. For Yakovlev the aircraft was viewed as a way of returning to designing Soviet fighter aircraft.
[
Because of the importance and complexity of the project, Alexander Sergeyevich Yakovlev assigned a large portion of his ]OKB
OKB is a transliteration of the Russian initials of "" – , meaning 'experiment and design bureau'. During the Soviet era, OKBs were closed institutions working on design and prototyping of advanced technology, usually for military applications. ...
to the development of the new VTOL fighter, with no fewer than ten chief engineers working simultaneously on what was called "Product 48" (the military had designated it ''Yak-41''). Over fifty designs were studied. One key problem was designing an aircraft with both vectoring thrust and an afterburner, which was essential for sustained supersonic speeds. A twin-engine design was considered, but abandoned as the loss of an engine on landing would result in an immediate roll to the side. Eventually it was decided that the best arrangement was a single vectoring nozzle located just behind the center of gravity, as well as dedicated vertical thrust jets positioned just behind the cockpit. A considerable amount of time was spent in the development of a flat, rectangular nozzle similar to that later employed on the American F-22 Raptor. Such a nozzle proved well-suited for the changes in configuration needed for both thrust vectoring and supersonic flight, and allowed for a thin, shallow tail. Ultimately, a circular nozzle was used, located between twin booms supporting the twin-finned tail.[
Parts subject to excessive heat from the engines during landing were manufactured of ]titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
, and no less than 26% of the overall aircraft was to be manufactured of graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...
or composite material
A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...
. Because of heat build-up, hovering was restricted to no more than 2 minutes.[
]
All three engines were controlled through an interlinked digital system, which was capable of controlling both engine start-up as well as modulating the thrust of all three engines during landing and hovering flight. Twin tandem reaction control jets were positioned at the wingtips, while a swiveling yaw jet was positioned under the nose.[
The cockpit was pressurized and air-conditioned. The small canopy was bulletproof in front. It hinged to the right, but because of a long dorsal spine it had no rear vision. The ejection seat was automatically armed as soon as the engine duct was rotated past 30 degrees with an airspeed of less than 300 km/h (162 kn / 186 mph). The instrumentation in the prototypes was simple and similar to that planned for the earlier Yak-36M. The production version was to have been fitted with an extensive avionics and weapons suite including doppler radar, laser-TV ranging and aiming, as well as a heads-up multifunction display (HUD) which worked in connection with a helmet-mounted missile aiming system as found on the Mikoyan MiG-29. This system allows the pilot to lock onto an enemy aircraft by turning his head as far as 80 degrees from front.][
The undercarriage was tricycle, and equipped with the latest multi-disc, anti-skid brakes. The steerable nose wheel retracted to the rear, while the main gear retracted forward.][
]
The top-mounted wing was similar to that of the Yakovlev Yak-36
The Yakovlev Yak-36, also known as ''Izdeliye V'', (NATO reporting name "Freehand") is a Soviet technology demonstrator for a VTOL combat aircraft.
Design and development
From 1960, the Yakovlev Design Bureau began work on a VTOL system, using ...
, though the outer panel swept back, and could be folded up for shipboard storage. The main engine was served by four side-mounted ducts as well as a row of large louvers along the upper surface to allow air to enter the engine during full power hovering. This engine was the R-79V-300, a two-shaft augmented turbofan with a bypass ratio of 1. Maximum thrust was 14,000 kg (30,864 lb). The rear nozzle could rotate from 0 degrees to 95 degrees for VTOL landing and hovering. The two lift engines were the RD-41 design, a simple single-shaft engine made mostly of titanium. Each had a thrust of 4,100 kg (9,040 lb). The engines were installed behind the cockpit at an angle of 85 degrees. Like the Yak-38, the engines received their air through eight spring-operated dorsal flaps, and the exhaust exited through a belly opening covered by two ventral doors.[
Yakovlev obtained funding for four prototypes. The first (48-0, with no callsign) was a bare airframe for static and fatigue testing. The second (48-1, call sign "48") was a non-flying powerplant testbed. The third and fourth (48-2 and 48-3, call signs "75" and "77") were for flight testing. While 48-1 remained unpainted, 48-2 and 48-3 were painted in overall grey, with a black radome and fin cap antennas.][
]
Operational history
The first conventional flight, using 48–2, took place at Zhukovsky on 9 March 1987, with chief test pilot Sinitsyn at the controls. He made the first hovering flight on 29 December 1989 flying 48–3, and used the same aircraft to make the first complete transition from vertical to high-speed flight and vertical landing on 13 June 1990. From April 1991, various kinds of rolling take-off and run-on landings were performed on normal runways and also "ski-jump" ramps at the lift jet center at Saky. Throughout its testing, the aircraft demonstrated excellent combat maneuvers.[ Chief test pilot Sinitsyn went on to set twelve new world class records, but as the Yak-41 designation was classified, the records were submitted under the fictitious name "Yak-141".][ As a result, the previously unknown aircraft came to be known in the west as the "Yak-141". In 1992, Yakovlev repainted both flying aircraft in olive/grey camouflage, with the Russian tricolor insignia, and painted a white "141" on both aircraft in place of their previous call signs, "75" and 77".][
]
On 26 September 1991, Sinitsyn made the first vertical landing on the aircraft carrier ''Admiral Gorshkov'' (ex-''Baku'') in 48-2. An hour later, Vladimir A. Yakimov landed 48-3 on the same deck. The pilots would go on to make eight flights from the ship until Yakimov made a hard landing on 5 October. The undercarriage ruptured a fuel tank, causing a serious fire. After almost 30 seconds, Yakimov ejected successfully, and was rescued from the sea. The aircraft was later repaired and placed on display.[ That same month the Soviet Navy announced that no further funds were available to continue the program. The factory at Smolensk had anticipated this and had not constructed the tooling for production.][
]
Yak-41 or Yak-141
The design was initially designated the Yak-41M by the Soviet military. Once testing commenced, and the two prototypes began accumulating numerous world class records, it became necessary to invent a designation for use in the west, as the name Yak-41M was classified. The designation Yak-141 was selected, and it was by this name that the aircraft became known to western allies, though officially the aircraft's designation remained Yak-41M within the Soviet military. In 1991 Lockheed-Martin entered into partnership with Yakovlev to further develop an aircraft they had always known as the Yak-141. Largely as a result of this agreement, by 1992 Yakovlev changed the aircraft's designation to Yak-141 for the two flyable prototypes. Series production in Russia could further change the designation.[
]
Cooperation with Lockheed
Following the announcement by the CIS
Cis or cis- may refer to:
Places
* Cis, Trentino, in Italy
* In Poland:
** Cis, Świętokrzyskie Voivodeship, south-central
** Cis, Warmian-Masurian Voivodeship, north
Math, science and biology
* cis (mathematics) (cis(''θ'')), a trigonome ...
in September 1991 that it could no longer fund development of the Yak-41M, Yakovlev entered into discussions with several foreign partners who could help fund the program. Lockheed Corporation
The Lockheed Corporation was an American aerospace manufacturer. Lockheed was founded in 1926 and later merged with Martin Marietta to form Lockheed Martin in 1995. Its founder, Allan Lockheed, had earlier founded the similarly named but ot ...
, which was in the process of developing the X-35
The Lockheed Martin X-35 is a concept demonstrator aircraft (CDA) developed by Lockheed Martin for the Joint Strike Fighter program. The X-35 was declared the winner over the competing Boeing X-32 and a developed, armed version went on to enter ...
for the US Joint Strike Fighter program
Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Italy, Canada, Australia, the Netherlands ...
, stepped forward, and with their assistance aircraft 48-2 was displayed at the Farnborough Airshow in September 1992. Yakovlev announced that they had reached an agreement with Lockheed for funds of $385 to $400 million for three new prototypes and an additional static test aircraft to test improvements in design and avionics. Planned modifications for the proposed Yak-41M included an increase in STOL weight to 21,500 kg (47,400 lb). One of the prototypes would have been a dual-control trainer. Though no longer flyable, both 48-2 and 48-3 were exhibited at the 1993 Moscow airshow. The partnership began in late 1991, though it was not publicly revealed by Yakovlev until 6 September 1992, and was not revealed by Lockheed until June 1994.[
]
Variants
;Yak-41
:The two flying prototypes and ground test article.
;Yak-41M
:Proposed production aircraft with large LERXs (leading-edge root extensions) and other improvements, particularly in the avionic suite.
;Yak-43
The Yakovlev Yak-43 was a Soviet VTOL (vertical takeoff and landing) fighter designed as the ground-based version of the ill-fated Yakovlev Yak-141, which failed to reach production. Like the Yak-141, the Yak-43 did not reach production.Gunston, ...
(Izdeliye 201)
:A proposed development of the Yak-41M 'Freehand' equipped with Kuznetsov Kuznetsov, Kuznyetsov, Kuznetsoff, or Kouznetsov (masculine, russian: Кузнецов) or Kuznetsova (feminine, russian: Кузнецова) is the third most common Russian surname, an equivalent of the English "Smith" (derived from a Russian word ...
NK-321 engines.
;Yak-141
:Designation originally applied to a single Yak-41 for disinformation and propaganda purposes when registering records with the FAI (Fédération Aéronautique Internationale
The (; FAI; en, World Air Sports Federation) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintai ...
) and later for promotional purposes by Yakovlev.
Operators
;
* Soviet Navy
** Soviet Naval Aviation
Surviving aircraft
* Yak-41M (s/n 48-2, call sign "75") is on display at the Central Air Force Museum
The Central Air Force Museum (russian: Центральный музей Военно-воздушных сил РФ) is an aviation museum in Monino, Moscow Oblast, Russia. A branch of the Central Armed Forces Museum, it is one of the world's la ...
at Monino. The aircraft is displayed in its 1992 livery with olive/grey camouflage markings.
* Yak-41M (s/n 48-3, call sign "77") is on display at the Yakovlev OKB Museum. The aircraft is displayed in its 1992 livery with olive/grey camouflage markings and "141" painted in white in place of the former call sign.[
]
Specifications (Yak-41)
See also
References
External links
Walkaround Yak-41 from Monino Museum (Russia)
at AeroFlight
at Military-Today
{{Authority control
Abandoned military aircraft projects of the Soviet Union
Carrier-based aircraft
1980s Soviet fighter aircraft
Twin-boom aircraft
Yak-141
The Yakovlev Yak-141 (russian: Яковлев Як-141; NATO reporting name "Freestyle"), also known as the Yak-41, is a Soviet supersonic vertical takeoff/landing (VTOL) fighter aircraft designed by Yakovlev. It was used for testing.
Design ...
Lift jet
Aircraft with auxiliary jet engines
Single-engined jet aircraft
High-wing aircraft
Aircraft first flown in 1987