India and Russia have signed a long-discussed preliminary design contract for India's fifth-generation fighter aircraft (FGFA), a variant of the Sukhoi PAK FA demonstrator.
The deal was signed during Russian president Dmitry Medvedev's official visit to New Delhi in December.
Hindustan Aeronautics chairman Ashok Nayak has valued the contract at $295 million. During its 18-month term, Indian designers will work with Sukhoi's designers in Russia, building in Indian requirements for the variant.
The deal was originally expected to be signed at the end of 2009, but was held up as the two nations hammered out issues relating to technology transfer and the cost of the programme.
Nayak tentatively suggests the co-developed FGFA's first flight could take place around 2017-18.
Asked whether India is coming to the project relatively late - the PAK FA prototype first flew in January 2010 and has since logged about 40 test missions - Nayak says the FGFA could be "far different from what is flying today". The next PAK FA will also have a more advanced engine, he says.
The current PAK FA is powered by two NPO Saturn "Item 117" engines, developed from the Item 117S design already flown on Sukhoi's Su-35 and a Su-27M testbed. The experimental aircraft's integrated flight control system controls the engines and all other major systems.
Sukhoi says other key design elements include the use of composite materials, advanced aerodynamic techniques and measures to reduce the aircraft's engine signature, which it claims results in an "unprecedented small radar cross-section in radar, optical and infrared range".
The PAK FA is also equipped with an advanced phased-array antenna radar, Sukhoi adds. Russia's Tikhomirov NIIP displayed an active electronically scanned array design for the fighter at 2009's Moscow MAKS air show.