Delays, challenges for Indo-Russian fighter

By Ajai Shukla

Business Standard, 15th May 12

Seven years before its scheduled completion, the defence ministry (MoD) has already announced a two-year delay in the Fifth Generation Fighter Aircraft (FGFA) that India and Russia will jointly develop.

Defence Minister AK Antony has been saying that the FGFA would join the Indian Air Force by 2017. On Monday, his deputy, MM Pallam Raju told parliament that “The fifth generation aircraft is scheduled to be certified by 2019 following which the series production will start.”

The FGFA is the flagship of the Indo-Russian partnership. Both countries say it will be the world’s most advanced fighter. But interviews with Indian designers who have overseen the project suggest significant disquiet. There is apprehension that the FGFA will significantly exceed its current $6 billion budget, because this figure reflects the expenditure on just the basic aircraft. Crucial avionics systems would all cost extra.

On the positive side, Indian designers say the FGFA project will provide invaluable experience in testing and certifying a heavy fighter aircraft that is bigger and more complex than the Tejas Light Combat Aircraft (LCA), India’s foundational aerospace achievement.

The Russian and Indian Air Forces each plan to build about 250 FGFAs, at an estimated cost of US $100 million per fighter. That adds up to US $25 billion each, in addition to the development cost.

The FGFA’s precursor has already flown. In Jan 2010 Russian company, Sukhoi, test-flew a prototype called the PAK-FA, the acronym for Perspektivnyi Aviatsionnyi Kompleks Frontovoi Aviatsy (literally Prospective Aircraft Complex of Frontline Aviation). Now, Hindustan Aeronautics Limited (HAL) will partner Sukhoi to transform the bare bones PAK-FA into an FGFA that meets the Indian Air Force’s requirements of stealth (near-invisibility to radar); super-cruise (supersonic cruising speed); networking (real-time digital links with other battlefield systems) and world-beating airborne radar that outranges enemy fighters.

But Sukhoi insists that the PAK-FA already meets Russia’s requirements, says NC Agarwal, the HAL design chief, who spearheaded the FGFA negotiations until his recent retirement. HAL worries that Russia might ask India to pay extra for further development, particularly the avionics that transform a mere flying machine into a lethal weapons platform. That would leave the $6 billion budget in tatters.

The IAF clearly wants a top-of-the-line FGFA. According to Ashok Nayak, who spoke to Business Standard as HAL’s chairman before retiring last Oct, the IAF has specified 40-45 improvements that must be made to the PAK-FA. These have been formalized into an agreed list between Russia and India, which is called the Tactical Technical Assignment.

A key IAF requirement is a “360-degree” AESA (airborne electronically scanned active) radar, rather than the AESA radar that Russia has developed. Either way, India would pay Russia extra: either in licence fees for the Russian radar; or hundreds of millions, perhaps billions, for developing a world-beating, 360-degree AESA radar.

Nor is the IAF clear on whether the FGFA should be a single-seat fighter like the PAK-FA, or a twin-seat aircraft like the Sukhoi-30MKI. A section of the IAF backs a single-seat fighter, while another prefers two pilots for flying and fighting a complex, networked fighter. During the ongoing Preliminary Design Phase (PDP), for which India has paid $295 million, a two sides will determine whether developing the PAK-FA into a twin-seat aircraft (inevitably more bulky) would reduce the FGFA’s stealth and performance unacceptably.

“The single-seat FGFA is essential for the IAF, and we will transform the Russian single-seat fighter into our single-seat version with a large component of Indian avionics. The twin-seat version will depend on the PDP conclusions,” says Nayak.

The PDP also requires Sukhoi to hand over design documentation to HAL, providing it a detailed insight into the design processes of the PAK-FA.  Since India took years to decide to join the FGFA project, HAL missed out the design phase entirely.

The 18-month PDP, which terminates this year, will be followed by the “R&D Phase,” which could take another 7 years, says the HAL chairman. The FGFA will be designed in both countries; some 100 HAL engineers already operate from a facility in Bangalore. Another contingent will move to Russia to work in the Sukhoi Design Bureau.

“Our boys will learn the Russian language; their way of working; their design rules; their design norms. We are left hand drive, while they are right hand drive. The Russians say they will part with all these things,” says Nayak.

But the most valuable learning, say HAL executives, will happen during the FGFA’s flight-testing. “Unlike the basic design phase, which we missed out on, we will actually gain experience during flight testing. This phase throws up dozens of problems and we will participate in resolving these, including through design changes.”

HAL engineers recount the complexity of flight-testing the Tejas LCA. “Fuel flow to the engine was a challenging issue. As the LCA flew, its centre of gravity shifted because fuel was consumed unevenly between its 7-8 fuel tanks. So we learned to balance the fuel between tanks, completely changing the design of this system during flight-testing. Similarly, we had to strengthen the wings when we mounted the R-73 missile. All this you learn only by experience,” says Agarwal.

Despite the LCA experience, HAL engineers believe that the 30-tonne FGFA is a far more complex challenge. They estimate that flight testing such an aircraft without Russian help might take 15 years, as long as the LCA.

HAL designers also relish the FGFA’s specific challenges. For achieving stealth, its missiles, rockets and reconnaissance payloads are concealed in an internal bay under the wings. Before using these, a door slides open, exposing the weapon for use.

The Russians clearly believe that HAL possesses useful capabilities, including the ability to design the AESA radar. Also attractive is India’s experience in composites.

“The LCA program has generated a high level of expertise in composite materials within the National Aerospace Laboratory and some joint teams. The FGFA requires “higher modulus” composites, which can withstand the 120-130 degree Centigrade temperatures that arise whilst flying at Mach 1.7 speeds,” says Agarwal.

Despite the continuing imponderables, HAL believes that the FGFA project provides genuine technological skills, far more useful than licensed manufacture. “We will pay some $6-7 billion to France for the licence to build the Rafale in HAL. In the FGFA project, a similar sum will bring in genuine design knowledge that will help us in the future.”