Russians reveal multi-axis nozzles

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Alexander Velovich/MOSCOW

Russian fighter engine manufacturers Lyulka and Klimov have separately unveiled two-axis thrust vectoring nozzle designs for their respective combat aircraft engine projects.

The nozzles for the Lyulka RD-33 and Klimov AL-31 turbofans were revealed at the 5th Moscow Aeroengine Show in June.

The Lyulka nozzle, designated the AL-100, provides up to 15° deflection in the vertical plane and 8° in the horizontal plane. It is intended for "a single-engine fighter", thought to be the Sukhoi S-54. The provision of thrust vectoring adds 60kg to the weight of the baseline AL-31 engine.

Klimov is also working on a two-axis thrust-vectoring derivative of its RD-33 turbofan, the RD-133. This engine has logged about 50h of tests on the ground stand, but it is uncertain when, or whether, flight testing will get under way. According to one Klimov source, MAPO is not providing adequate financing for the programme. The RD-133 has a maximum deflection of 15° in both the horizontal and vertical planes.

Other modifications of the RD-33 family on which the company is working include the RD-33N. This has the accessory gearbox mounted lower to allow it to be accommodated in the Chinese Chengdu FC-1 fighter, now in development.

A further modification, the VKS-10, is thought to be for the Chengdu F-10. Klimov has already delivered four RD-33Ns to China and expects a contract for a production batch to be signed later this year.

Lyulka Saturn also unveiled the AL-55 at the show. This is a small turbofan with a thrust vectoring nozzle intended to power next-generation advanced trainers and light fighter aircraft. The AL-55 will be available in afterburning and non-afterburning configurations, rated respectively at 20kN (4,400lb) and 29kN of thrust.

The dry version is intended for installation in the MAPO MiG-AT advanced trainer, powered by the Snecma-Turboméca Larzac. The Russian air force demands that its future trainer is powered by a Russian-produced engine.

Negotiations on Larzac licence production are deadlocked, according to Moscow sources, so Lyulka hopes that it is offering a winning solution, coupled with 30% thrust increase.

Lyulka chief designer Mihail Goikhenberg says that a pair of afterburning AL-55Fs could also power a next-generation lightweight multirole fighter.

Sukhoi has also demonstrated a "quasi-two-axis" thrust vectoring capability on its Lyulka AL-31-powered Su-30MKI intended for the Indian air force. A senior Indian air force delegation visited Moscow this month to discuss progress on the programme.

The Su-30MKI nozzles have only single-axis movement, although they have been realigned to operate at a 32° outward incline from the vertical plane. This realignment provides a considerable lateral force when the nozzles are moved differentially.