The Yak-41 is a supersonic V/STOL (Vertical/Short Take-Off and Landing) naval fighter. Although it never entered operational service, some of it's advanced technology will see application on Lockheed-Martin's F-35 fighter.
Yakovlev's first experiment with jet-lift was the primitive Yak-36 (NATO: Freehand), which made its first vertical take-off on 24 March 1966. Vertical take-off on this aircraft was achieved by locating a swivelling jet exhaust nozzle for each of it's two engines directly under the aircraft's centre of gravity. The experience thus gained led to the larger Yak-38 naval fighter-bomber (NATO: Forger), which first flew in 1970 and entered service with the AV-MF (Fleet Naval Aviation) on 6 October 1976. This time, twin swivelling exhaust nozzles for the single main engine were combined with two dedicated lift engines located in the forward fuselage. Unfortunately, the technology incorporated in the Yak-38 was still immature and the type encountered numerous technical and operational problems.
Lack of thrust from the Yak-38's engines severely limited the possible weapons payload and the amount of fuel that could be carried, whilst high fuel consumption resulted in very poor range. No radar was carried, to save weight, which limited it's ability to carry out air defence missions. In addition, aircraft serviceability remained low throughout the type's service life.
While development work on the Yak-38 was still proceeding, Yakovlev was authorised in 1975 to begin work on a more capable replacement, for use in the fleet air defence role from AV-MF aircraft carriers. After exploring a number of enhancements to the Yak-38 airframe it was concluded that only a much larger airframe with more powerful engines could hope to provide the neccessary performance. Designated Yak-41, the resulting new design retained the same basic layout as the Yak-38 but was almost 30% larger and twice as heavy (in empty weight) as its predecessor. A Fazotron S-41M Zhuk radar was installed in the nose.
To power the Yak-41, a new engine was developed. The R-79 was fitted with an afterburner to allow supersonic performance, while the single swivelling exhaust nozzle was located between two deep tail booms. Two new RD-41 lift engines were installed behind the cockpit, inclined forwards by 5 degrees and exhausting through nozzles which could deflect by +/- 12.5 degrees to give thrust vectoring. During a vertical take-off or landing the main nozzle pointed 90 degrees downwards, while for a short take-off it was deflected at 63 degrees.
In 1977 the decision was made to proceed with full development of the Yak-41, and in the following year construction began of the aircraft carrier Baku (later renamed Admiral Gorshkov), which was expected to include the Yak-41 in it's air wing.
In 1985 it was decided to make the Yak-41 a multi-purpose fighter rather than a dedicated interceptor, under the designation Yak-41M. The design of the additional aircraft systems required caused a delay in the development programme. Two static test Yak-41Ms were build - the first (48-0) was used for static and fatigue tests, while the second (48-1, bort '48' yellow) was employed performing engine ground running trials in both cruise and VTOL modes. These two airframes were followed by two flight-rated airframes '75' white (48-2) and '77' white (48-3).
The first flight was made on 9 March 1987 in conventional mode, and the first hover was carried out on 29 December 1989. During April 1991 a series of flights gained 12 FAI recognised world records for VTOL aircraft, which were recorded under the designation Yak-141. This designation was later re-used for the proposed export variant of the aircraft.
On 26 September 1991 the first landing on board Admiral Gorshkov was successfully accomplished. Unfortunately, on 5 October 1991, aircraft '77' white experienced a landing accident aboard the carrier which resulted in it being grounded. Economic reality caught up with the Yak-41M in November 1991 when a drastically reduced defence budget for the newly created CIS left the programme without any further state funds.
In September 1992 aircraft '75' white was repainted as '141' white and displayed at the Farnborough Air Show, in an attempt to attract foreign funding, but this ploy was unsuccessful and development ceased in 1993.
The production version was planned to feature uprated engines allowing take-off with more weapons or additional fuel. A prototype two-seat trainer was never completed. An advanced stealthy version designated Yak-43 remained only a project.
During the summer of 1995, Lockheed Martin announced a teaming arrangement with Yakovlev to assist in the former's bid for the JAST (Joint Adanced Strike Technology) competition. Yakovlev's knowledge of jet lift technology was to prove invaluable. Lockheed Martin was subsequently selected to build a demonstrator aircraft, the X-35, which went on to win the JSF (Joint Strike Fighter) competition and will soon become a production fighter as the F-35.
One of the key problems with the Yak-41M jet-lift system was the need to engage afterburner for vertical take-off or landing. At land bases this soon resulted in damage to the runway, while the Admiral Gorshkov was fitted with a special water-cooling system to absorb the heat from the jet blast. Hence, the Yak-41M was in no sense a Harrier-style go-anywhere aircraft.
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