23 July 2014

Fifth Generation Fighters and the IAF

21 Jul , 2014

SU-30 MK-1 Formation

The capability of any modern fighter is usually way ahead of its predecessors, especially so if it is replacing decades-old planes such as the MiG-21 and the MiG-27. This is even more applicable to the leader of the pack of six of the world’s best fighter jets. Other air forces in the neighbourhood are also acquiring combat aircraft of similar capability, thus nullifying the IAF’s advantage. But the true game changer for the IAF, something that may give its potential adversaries many sleepless nights in the years ahead, is the Fifth Generation Fighter Aircraft (FGFA).

These are exciting times for the Indian Air Force (IAF). After years of helplessly watching its combat assets dwindle or fade into obsolescence, the service is finally shifting into top gear and inducting an impressive range of modern equipment that should enable its transformation into a potent strategic force. Combat aircraft constitute the sharp end of air power, so the procurement of large numbers of Su-30 MKI air dominance fighters and the impending final operational clearance of the indigenous Tejas Light Combat Aircraft, possibly by the end of the year, are reason enough for cheer. And no other recent item has captured the public imagination like the high-stakes contest for the IAF’s Medium Multi-Role Combat Aircraft (MMRCA) that recently threw up the Dassault Rafale as the winner. Yet these aircraft, important as they are, will not make a dramatic difference.

All fifth generation fighters use a high percentage of composite materials in airframe construction.

The capability of any modern fighter is usually way ahead of its predecessors, especially so if it is replacing decades-old planes such as the MiG-21 and the MiG-27. This is even more applicable to the leader of the pack of six of the world’s best fighter jets. Other air forces in the neighbourhood are also acquiring combat aircraft of similar capability, thus nullifying the IAF’s advantage. But the true game changer for the IAF, something that may give its potential adversaries many sleepless nights in the years ahead, is the Fifth Generation Fighter Aircraft (FGFA).

The US Lead

The term “Fifth Generation Fighter Aircraft” has been around for decades, especially in the United States. It is more marketing hype than a precise definition. In the early 1970s, American researchers identified stealth, speed and manoeuvrability as key ingredients of a next-generation air superiority fighter. The US Advanced Tactical Fighter project of May 1981 ultimately resulted in the production of the Lockheed Martin F-22 Raptor. Designed mainly for dogfights against rival jets, the F-22, that became operational with the US Air Force in December 2005, features full stealth, an advanced Active Electronically Scanned Array (AESA) radar and huge computing power that creates a single “sensor fusion” picture using data from an array of embedded sensors and data links.

Dassault Rafale B

It also has super-manoeuvrability and the ability to super-cruise i.e. fly at supersonic speeds without the use of afterburner rather than just making short fuel-guzzling supersonic sprints with afterburner engaged. That is not all. Some F-22 Raptors were recently upgraded with enhanced air-to-ground strike capability that makes it even more lethal and survivable in combat, a true multi-role combat aircraft. The USAF recently received the last of its tally of 187 of these prized jets at a cost of nearly $150 million apiece, a far cry from its original plan to acquire 750 aircraft.

For many years, the F-22 Raptor was the world’s only combat-ready fifth-generation fighter. The US rather selfishly refused to share it even with its closest allies. But competitors are gradually emerging. Designers in many countries are striving to make fighters with high-performance airframe, all-aspect stealth or at least a very high degree of stealth even when armed, powerful engines with low Infra-red (IR) signature, Low Probability of Intercept Radar (LPIR), advanced avionics and highly integrated computer systems capable of networking with other elements within the combat theatre to achieve a high degree of situational awareness. Effective sensor fusion is indispensable for the pilot to be able to utilise the torrent of information that sophisticated on-board sensors provide. All fifth generation fighters use a high percentage of composite materials in airframe construction in order to reduce Radar Cross-Section (RCS) and weight. Stealth technology including measures to reduce acoustic and visual signatures is also essential for any jet to be deemed truly fifth-generation. However, stealth shaping comes at a price. It can severely degrade the handling characteristics of the aircraft. So the right balance has to be struck between stealth, manoeuvrability and affordability. And stealth technology hardly renders fighters invisible. There are advanced sensors as well as some surprisingly low technology ones that can detect stealth aircraft.

The Russian T-50 is expected to end total domination by the United States in the stealth aircraft regime for a quarter of a century…

Besides the F-22 Raptor, the only other fifth-generation aircraft to make its debut has been the US Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF). The JSF programme has been plagued by delays and cost overruns leading to an estimated cost per plane of $135 million that includes development cost and projected inflation. It is expected to enter operational service with the USAF around 2015. Although the Pentagon says it plans to buy 2,443 F-35 jets, it is a fairly safe bet that these numbers will be slashed, just as they were for the F-22. The F-35 has a more conventional shape than the F-22 which makes it more manoeuvrable in air combat though with a moderate compromise in stealth profile. It has a smaller AESA radar but with higher computing power, embedded sensors and sensor fusion. It lacks super-cruise and super-manoeuvrability. Still it is claimed to be of fifth-generation pedigree.

Russia’s Response: The Sukhoi PAK-FA

Next in line and of singular interest to the IAF is the Sukhoi PAK-FA (T50), under development by Sukhoi OKB for the Russian Air Force. PAK-FA is the Russian programme title that in translation approximates to “Future Aviation Complex – Frontline Aircraft”. T-50 is the prototype version and it should eventually get a regular Sukhoi variant number. The Fifth Generation Fighter Aircraft (FGFA) is the somewhat prosaic designation of the planned Sukhoi/Hindustan Aeronautics Limited (HAL) programme to develop an India-specific variant. It too will eventually get a more distinctive Indian name, hopefully denoting ferocity in keeping with its capabilities.

F-35C Lightning II

The T-50 made its first flight on January 29, 2010, and completed 100 test flights on November 03, 2011. Three prototypes are currently under testing; the third is reportedly equipped with AESA radar. Initial weapons trials are expected to begin this year. There may be up to 14 test aircraft by 2015.

The Sukhoi T-50 incorporates technology from the Su-47 and the MiG-1.44 and is intended to replace the large MiG-29 and Su-27 fleet of the Russian Air Force. It is designed to counter the US F-22 Raptor and F-35 Lightning II in traditional Beyond Visual Range (BVR) and Within Visual Range (WVR) air combat. The Russian Defence Ministry defines “fifth generation” to include stealth technology, supersonic cruising speed and highly integrated avionics, electronics and fire-control systems. The T-50 fully fits the bill; indeed it is expected to end total domination by the United States in the stealth aircraft regime for a quarter of a century. Its internal and external weapon load is likely to be somewhat larger than that of the F-22. The T-50 also has other attributes superior to the F-22 such as exceptional thrust/weight ratio, extreme agility as a result of its advanced aerodynamic design and 3-D thrust vectoring and leading edge vortex control integrated with an advanced digital flight control system. It has exceptional combat endurance thanks to its 25,000lb internal fuel capacity. Its shape will probably deny it the critical all-aspect stealth performance of the F-22 in BVR air combat and deep penetration strike roles. However, its extreme agility should more than make up for these shortcomings.

Mig-27

The Sukhoi T-50 has looks to kill, a sleek, graceful yet deadly form, often compared to the Northrop YF-23 Black Widow. It has a main trapezoid wing with slats, ailerons and movable leading edge extension, besides all-moving horizontal and vertical tails. The fuselage houses twin engines and their inlets and is suitably flattened with ample space for internal payload, two main weapon bays between the engine nacelles yet generates some lift. The main bays are augmented by triangular section bays at the wing root. Its overall shape with the smoothly blended wings and the integration of thrust vectoring with all-movable surfaces constitutes what is claimed to be an “integral aerodynamic design”. It minimises RCS and drag. Composites are used extensively and comprise 25 per cent of its weight and almost 70 per cent of its outer surface. The titanium alloy content of the fuselage may be as high as 75 per cent.

As important as stealth is, the Sukhoi design bureau has not gone overboard with it and certainly not to the extent of reducing the jet’s aerodynamic performance. For one thing, the cost of extreme stealth is prohibitive; for another, stealth in the real world is likely to be far less effective than predicted; even dirt stuck to the airframe can degrade it. The enemy would probably employ a mix of ground and airborne radars operating at various frequencies as well as a variety of other sensors to attempt to detect stealth aircraft. Some experts are critical of the way the PAK-FA abandons stealth in the rear quarter altogether. However, considering its superior aerodynamics, high speed and high altitude of operation, this may not be unwise, as the PAK-FA can easily evade a pursuing enemy. In any case, in close combat, Infra-Red Search and Track (IRST) systems and IR missiles are far more effective than radar-based ones. Hence RCS reduction to evade radar-guided missiles becomes relatively unimportant.

Northrop YF-23 Black Window

The new 117C (AL-41F1) power plant fitted on the T-50 is a fifth generation custom-built engine that incorporates IR and RCS reduction measures. The engine produces a maximum thrust of almost 15,000 kg (147kN), giving a thrust-to-weight ratio of 10.5:1. It has Full Authority Digital Engine Control (FADEC) to facilitate smooth engine operation even during extreme manoeuvring. The PAK-FA is one of very few fighters designed from the start with thrust vectoring. Each engine is able to independently vector its thrust upwards, downwards or side-to-side. Vectoring one engine up and the other down simultaneously can produce a twisting force, making this the first fifth-generation fighter with full 3-D thrust vectoring along all three aircraft axes: pitch, roll and yaw.

The cost of extreme stealth is prohibitive; stealth in the real world is likely to be far less effective than predicted…

The Sukhoi T-50 has an amazing climb rate of the order of 350 metres per second. While the jet’s maximum speed is 2,600 km/h it can comfortably super-cruise at 1,800 km/h. Its range is between 4,000km and 5,500km and service ceiling around 20,000 metres. It has a maximum take-off weight of 37,000 kg, with maximum weapons load of 7,500 kg. It may have one, possibly two, GSh-301 30mm cannon. With perhaps eight internal missile suspension points, two body bays and two smaller side bays, it is capable of carrying a bristling mix of missiles.

A key T-50 capability is data fusion. Inputs from infrared sensors, AESA radar and visual scanners are electronically merged and fed to the pilot in an easy-to-read form. Combined with automatic target tracking, this is expected to give the pilot a view of the tactical airspace perhaps superior to that seen by AWACS aircraft. However, a lone pilot might still be at risk of information overload. Hence the Sukhoi/HAL FGFA offers a return to the two-seat configuration common in fourth-generation strike fighters like the Su-30MKI, allowing in-flight workload to be shared.

Fly High, Fly Fast, Fight Deadly

The future of air combat is increasingly moving towards high speed, high altitude engagements. And America continues to be in the lead in developing military aircraft technology, as it has for the last seven decades or so. That is why, after the Vietnam War, no adversary has been willing or able to engage the US in a major air campaign. However, with its economy still in considerable difficulty, the US is warning that orders for the Lockheed Martin F-35 Lightning II will be cut if costs continue to rise. Large scale procurement of the F-35 has already slipped into the 2020s. In fact, major aircraft development projects around the world are experiencing significant delays. Thus many of the combat aircraft types in service today will continue to form part of frontline fleet well into the next decade. Even though these designs are around 40 years old, there simply is nothing affordable to replace them. At the same time, the impressive progress in Unmanned Aerial Vehicle (UAV) technology means that the future of manned combat aircraft is itself being questioned.

PC-7 Mk-II trainer aircraft

A side effect of the delay in the US F-35 programme is that the Russians have had more than two decade to develop an effective counter. And with the Sukhoi PAK-FA they seem to have succeeded in large measure. When the PAK-FA becomes operational it will have profound implications for air combat. Most US analyses of relative combat capabilities assume that enemy fighters can be easily detected and tracked by Airborne Warning and Control Systems (AWACS) and other Intelligence, Surveillance, and Reconnaissance (ISR) systems, permitting friendly fighters to choose the time, place and type of engagement. This means that aircraft like the F-15, the F-16 and the F/A-18 generation of fighter jets armed with BVR missiles, will engage mainly in BVR combat and far less frequently in WVR combat. However, this may not hold good any longer. It is possible that there will be a resurgence of WVR combat since aircraft with significant stealth capability like the PAK-FA, may be able to sneak in close to their opponents without being detected and launch weapons like the Vympel R-73 (AA-12) medium-range missile or the improved Vympel R-73 (AA-11) short-range missile. Even the US F-22 Raptor will lose its overwhelming tactical advantage when fighting against the PAK-FA. And the AWACS itself will become increasingly more risky to operate because the PAK-FA, which may be armed with ultra-long range missiles like the 200-400 km range Novator K-100-1 “AWACS killer”, might not be detected in time to avert an attack.

Jewel in the IAF’s Crown?

In December 2010, India and Russia signed an initial agreement to jointly develop and produce the FGFA. This could eventually crystallise into India’s biggest and most important defence deal ever. In October 2011, it was reported that the IAF planned to induct 166 single-seat fifth-generation fighters. Presumably they will be of the same type as the PAK-FA or very similar. In addition, the IAF will acquire 48 dual seat variants of the FGFA which will be assembled by HAL. Each of these fifth-generation planes is likely to cost approximately $100 million and the total size of the deal to develop and produce the IAF’s projected fleet is likely to touch $36 billion by 2030. Russia is planning on 2015 as the date for operational trials of the PAK-FA, so the IAF can expect its own aircraft to enter service no earlier than 2017, possibly some years later.

J-20 Mighty Dragon

It is not clear how different the FGFA will be from the PAK-FA. Initially the IAF seemed rather keen on a two-seat version, but the thinking seems to have changed. Some experts believe that since Russia’s T-50 project was already in an advanced stage before India decided to join, the scope for modification was rather limited. Apart from this, there may not be sufficient technical expertise in this country to undertake extensive fighter aircraft remodelling as experience with the design and development of the HAL Tejas shows. And yet, being a partner in the futuristic PAK-FA project does give the country’s aerospace industry an opportunity to imbibe new skills and critical technologies. This is quite different from the other option of procuring the F-35 Lightning II from the US off-the-shelf, as some experts have advocated.

However, there is a major deficiency in the IAF’s preparations to operate the FGFA. Sadly, the government does not seem to be seized of the urgency of remedying the service’s lack of something as fundamental as a basic trainer aircraft. In fact, the IAF has been without a basic trainer since July 2009. Yet its likely replacement, the Swiss-made turboprop trainer Pilatus PC-7 Mk II, is not expected to be inducted before 2013. The IAF’s training schedule has already suffered much and even after the new trainer planes arrive, it will take considerable time to get it back on track. Pilots need years of training to be ready to operate modern fighter aircraft and weapon systems. And the youngsters undergoing initial training today will form the backbone of the fighter fleet a decade or so from now, so the stark possibility is that the IAF may not have enough suitably trained pilots to fly the FGFA.

Sadly, the IAF has been without a basic trainer since July 2009…

Meanwhile China’s military is rapidly modernising and the capability differential between China and India is widening. Apart from conventional combat aircraft like the Chengdu J-10 and the Shenyang J-11which it is building in large numbers, it is also developing its own J-20 stealth plane. The J-20 Mighty Dragon (NATO reporting name Black Eagle) is a single-seat, multi-role fighter, being designed by Chengdu Aircraft Industry Group for the People’s Liberation Army Air Force (PLAAF). Two J-20 prototypes were ready in November 2010 and the first flight took place in January 2011. Opinions are divided on whether the J-20 will emerge as a true fifth-generation aircraft with stealth and other key capabilities similar to the F-22, F-35 and PAK-FA or whether it is likely to incorporate mainly obsolete technology, meaning that the threat posed by it is greatly exaggerated. The Chinese are still heavily dependent on Russia for advanced fighter engine technology. The J-20 will almost certainly be flying with Russian engines for years to come. Some experts believe it may eventually morph into a stealthy ground attack jet rather than an air superiority fighter of the F-22 or PAK-FA class. In any case, the J-20 is unlikely to enter service before 2018-2020.

As for Pakistan, India’s plans to induct the FGFA in large numbers means that it will have to play yet another game of catch up. The FGFA is simply a class apart and its induction into the IAF will leave the Pakistan Air Force (PAF) with no credible counter. The US has steadfastly refused to supply the F-22 even to its closest friends and is likely to pick and choose the countries to which it may agree to sell the F-35 Lightning II. One does not need to be a prophet to predict that the PAF will make every effort to acquire the Chengdu J-20 from its all-weather friend China. However, what remains to be seen is whether the J-20 will come anywhere close to matching the FGFA.

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