FGFA facing headwinds?

The Fifth-Generation ‘Striker’

Sayan Majumdar writes that despite technical progress of the PAK-FA a.k.a. T-50 Fifth- Generation Fighter Aircraft (FGFA), there are serious ‘headwinds’, with Russia scaling down its purchase commitments almost continuously and Indian Defence Minister confirming that no progress has been made on the FGFA since mid-2013. Even if the Indo-Russian contract is signed this year, the IAF will not receive the first FGFAs before mid-2023.

The PAK-FA a.k.a. the T-50 FifthGeneration Fighter Aircraft (FGFA) prototype's maiden flight, piloted by Sergey Bogdan, took place on 29 January 2010, from KnAAPO's Dzemgi Airport and lasted 47 minutes. This was to verify manoeuvrability and normal operation of engines and main systems. Importance of the T-50 project may be summed up in the words of Mikhail Pogosyan, Sukhoi’s Director General, on launch of the test campaign: “Today we've embarked on an extensive flight test programme of the fifthgeneration fighter. This is a great success of both Russian science and design schools. This achievement rests upon a cooperation team comprised of more than a hundred of our suppliers and strategic partners. The PAK- FA programme advances Russian aeronautics together with allied industries to an entirely new technological level. These aircraft, together with upgraded 4th generation fighters will define Russian Air Force potential for the next decades. Sukhoi plans to further elaborate on the PAK-FA programme, which will involve our Indian partners. I am strongly convinced that our joint project will excel its Western rivals in cost-effectiveness and will not only allow strengthening the defence power of Russian and Indian Air Forces, but also gain a significant share of the world market.”

That first flight invoked considerable curiosity among the military aviation community worldwide as it was the first fighter to have 'emerged' in Russia after dissolution of Soviet Union. In contrast to the common perception of being an uncompromising air superiority fighter to challenge the United States Lockheed Martin F- 22 Raptor, this Vayu writer feels that in the T- 50 programme, the Russian aviation industry has begun an ‘ initial point’ to develop a formidable strike fighter (conceptually similar to the

Dassault Rafale and Boeing F-15E Strike Eagle) while retaining full capabilities of being a formidable adversary in the airto-air combat arena. Progress of the T-50 project has been relatively smooth and swift and on 3 November 2011, the T-50 prototypes achieved their 100th flight. The 200th flight was achieved in January 2013 with credit due to five Sukhoi test pilots : Sergei Bogdan (who performed the maiden flights on the four prototypes), Roman Kondratyev, Yuri Vashchuk, Sergei Kostin and Taras Artsebarsky.

India was initially to procure 144 Fifth Generation Fighter Aircraft (FGFA) for fulfilling air defence missions in critical sectors, and as a long-range strike aircraft. With an internal fuel of 25,000-lb plus supercruise attributes, the aircraft would be able to attain a combat radius of over 2,000-km, further boosted by Air-to-Air Refuelling (AAR).

Describing the T-50

Displaying standard attributes of Very Low Observable (VLO) airframe design, especially in the forward and upper fuselage, inlets, wings and tail surfaces, the T-50 has a flat appearance with a humped canopy area optimised for low-level stealthy flight over enemy territory. For the aforesaid ingress, the FGFA will (like the Sukhoi Su-35S) employ a dual mode GLONASS (Global Navigation Satellite System)/GPS receiver (military grade GLONASS signals will be made available to India and Russia) and Kalman filter based inertial navigation suite, with a Ring Laser Gyroscope (RLG). The combination of Active Electronic Scanned Array (AESA) radar and automation and high degree Artificial Intelligence ( AI) systems (often referred by the Russians as the second pilot) will reduce pilot workload.

The T- 50 is superficially similar to Lockheed Martin’s F-22 Raptor with a quasitrapezoidal wing with Leading Edge Root Extensions (LERX) (with vortex controllers) and traditional control surfaces. The vertical stabilisers angled out at about 25-degrees are trapezoidal and fully movable while the 'tail sting' houses the brake parachute and a rearward facing radar similar to the Phazotron N012. The Infra-Red Search & Track (IRST) will be based on OLS-35 highly integrated with other electro-optical systems by 101KS Atoll system comprising 101KS-V, 101KS-O, ultraviolet 101KS-U and 101KSN. Composites ( polymer carbon fibre reinforced plastic) comprise 25 per cent of the weight and 70 per cent of the outer surface with high degree of titanium content. The Radar Cross Section (RCS) of the forward section is aimed to be 40 times smaller than that of the Sukhoi Su30, or about 0.5-square metres. This will ultimately decrease to 0.01-0.03 square metres after application of Radar Absorbent Material ( RAM) coating. According to sources, Hindustan Aeronautics Limited (HAL) would contribute largely on the composites, mission computers, avionics and cockpit displays.

Two tandem main weapon bays in the centre fuselage between the engine nacelles measure between 4.5 to 5 metres long (doors of those have saw tooth-shaped edges) augmented by bulged, triangularsection bays at the wing root. The two main weapon bays can accommodate a total of six R-77 Beyond Visual Range Air-to-Air Missiles (BVRAAM) or appropriate air-tosurface ordnances developed by Tactical Missile Weapon Corporation while each triangular-section bays at the wing root can accommodate a single Close Combat Missile (CCM) each. For combat operations where stealth requirements are not paramount there are provisions for six additional external hardpoints that include two under the air intakes. It may be reasonable to assume that as per Russian air combat tactics, multiple missile shots will be conducted during opening phases of an engagement at enemy high-value targets usually with different terminal homing heads to increase the kill probability (pK). This necessitates the carriage of at least ten BVRAAMs, thus attachment of a stealth pod with additional missiles may be a common feature especially when operating within friendly airspace.

It is interesting that India’s Astra BVRAAM project, guided and led by the Defence Research and Development Laboratory (DRDL) appears to be optimised for internal carriage. The single stage, smokeless, solid fuelled Astra with a length of 3570 mm, body diameter of 178 mm and weight of 154 kg, is powered by high energy lithium thermal batteries making it the lightest in its class and thus enjoying a wide range of applications. T-50s armed with this BVRAAM will be capable of destroying high manoeuvring 9 g enemy targets at high altitude in the head-on mode at a range of 80 km and in tail-chase mode at 20 km, thanks to the missile’s low drag, low aspect ratio wings and capability to pull a lateral acceleration of 40g in both yaw and pitch planes which means it should be able to engage a non-manoeuvring targets well in excess of 100 km and capable of operating in the altitude bracket from sea level to 20 km.

Sparse details have emerged of the Russian RVV-SD BVRAAM, which was unveiled for the first time at MAKS-2011. It will be interesting to learn whether it will be equipped with a dual-band (active radar and passive radiation) seeker. At least four external hardpoints can accommodate the dual- mode solid- fuelled RVV- BD BVRAAM, which is capable of fulfilling the BVR role for ‘outer-air battles’ by taking out enemy Airborne Early Warning and Control (AEW&C) and AAR platforms at the initial stages of conflict. The RVV-BD weighs 510 kg, has a range up to 200 km and is capable of destroying targets with overload up to 8g at an altitude from 15 m to 25 km.

The T- 50 is to be equipped with Tikhomirov NIIP N050 ( further development of Irbis- E) X- band AESA radar in the nose with a 1-metre antenna containing 1,526 solid- state transmit/ receive modules by NPP Pulsar, with a range of about 400 km against a 1 metre square RCS target. With such attributes, N050 will remain fairly effective against ground and as well as stealthy airborne targets employing active countermeasures, and will be supplemented by long-wavelength L-band radar antennae on the wing leading edges, specifically for detection of stealth targets. The surfaces of the radar arrays are also angled off from the vertical plane, helping to 'deflect' enemy radar signals. Additionally the covers of the radar arrays are selective, letting through their own signals but blocking other frequencies. The array compartments are also edged with radar-absorbing 'curtains' to reduce possible leaks of these amplified signals. The third and fourth flying T-50 prototype flighttested the fighter's composite cutting-edge avionics suites that might well include the Polyot S- 111N Intra- Flight Data Link (IFDL).

Kinematics have traditionally been a key strength of the Sukhoi design bureau and variable-cycle AL-41F1 (Izdelye 117) turbofan engines with 12 tonnes of dry thrust will enable the aircraft to supercruise at Mach 1.5 effectively enhancing the range of BVRAAMs by 30 per cent. With afterburner, 14.7 tonnes of thrust will be

obtained. Further development of more powerful engines is projected to feature three- dimensional thrust vectoring and complex automation systems, to facilitate super manoeuvrability for domination of close combat engagements plus defeat of hostile missile shots.

The engines are placed wide apart in isolated pods, with air intakes located further apart in respect to the vertical and horizontal planes than the engines, creating a curvature that hides the compressor and reduces the frontal RCS. The engines are also placed at an acute angle relative to the vertical plane, allowing thrust vectoring, as mentioned earlier, in the longitudinal, transverse and travel channels. The engine nozzles point outwards, which transfers a significant portion of the control of the aircraft to them even at low altitudes.

The T-50 is fitted with an unusually robust high sink rate undercarriage, intended for operations from Short TakeOff and Landing (STOL) operations from short unprepared runways which will also be an added asset while operating from aircraft carriers in the future especially if the aircraft is fitted with strengthened undercarriage and an arrester hook from baseline models.

Facing headwinds

However, despite technical progress of the programme, the T-50 and its Indian variant, the Fifth Generation Fighter Aircraft (FGFA) appear to be facing headwinds. According to sources in Russia, that country has been scaling back its purchase commitments almost continuously since last year, with the most recent statement coming from Deputy Defence Minister in charge of Armaments, Yuri Borisov, who stated in March 2015 that the Russian Ministry of Defence would dramatically scale back its procurement of the new fighter. It is understood that the Russian Air Force is slated to receive, at least initially, only a single squadron of twelve production aircraft, down from an earlier commitment of 55 fighters, which itself was reduced from a much larger prospective order.

Then, in early August 2015, Indian Defence Minister Manohar Parrikar confirmed that no progress has been made on the FGFA project since June 2013, when the preliminary design phase was concluded following a contract signed in December 2010. The preliminary design phase was to be followed by signing of a full scale R&D contract, which would include prototype development in advance of actual production. However, the Indian side, which is expected to fund around half of the entire programme, and indeed has already spent nearly Rs 1,500 crore (ca. $230 million) on preliminary design, is expected to receive only a 13 per cent work share in industrial terms.

Uncomfortable with the scope of industrial cooperation relative to the financial burden, the Indian Government has held off on committing to the R&D contract. Under the terms of the draft R&D contract, the IAF would have begun receiving its first FGFAs 94 months (7 years and 10 months) after contract signature, which would mean even if the contract were signed this year, the IAF will not receive its first FGFA before mid-2023.