Beyond the MMRCA : the AMCA
The Advanced Medium Combat Aircraft
With formal announcement that the MMRCA programme has closed, with a limited purchase of 36 Rafales being negotiated, ADA’s advanced medium combat aircraft (AMCA) might just be the panacea that the IAF is hoping for. Based on the joint workshop organised by SAS and ORF, this is a detailed look at the AMCA programme, highlighting key areas of concern.
On 26 May 2015, The Society for Aerospace Studies, publishers of the Vayu Aerospace & Defence Review, held a joint workshop with the Observer Research Foundation (ORF), in New Delhi covering the twin topics ‘Beyond the MMRCA : Numbers and Missions’ and ‘Fast Tracking the AMCA.’ A detailed look at the AMCA programme, highlighting key areas of concern is published here, following on from a summary published in Vayu IV/2015.
Thirteen years from concept to closure”: the Indian Air Force’s tender for a Medium Multi-Role Combat Aircraft ( MMRCA) has been formally cancelled. Instead, a limited purchase of 36 Dassault Rafales is being negotiated without the transfers of technology and local production envisaged in the original RFP for the MMRCA. Cancellation of the tender to locally produce the winning candidate, Rafale, is compounded by the fact that fighter strength of the IAF is diminishing alarmingly. The IAF already operates a wide variety of aircraft types imposing significant strains on logistics, training budgets, as well as having an impact on force synergy. The acquisition of a ‘mere’ two squadrons of Rafales will only add to these issues. It is in this scenario that many believe that ADA’s Advanced Medium Combat Aircraft (AMCA) may just be the panacea that the IAF is hoping for.
The AMCA programme, while still very early into its design and development phase, is believed to hold immense potential to replace the wide range of legacy IAF aircraft. The AMCA will, at the same time, increase the force’s capabilities as the aircraft will be a generation ahead of what the IAF currently fields, or is considering, for its requirements. Development of ADA’s Light Combat Aircraft (LCA) has over the last 30 odd years certainly created a reliable aeronautics eco- system for the AMCA programme, making it a realistic and deliverable programme. Many believe that, if the IAF were to throw their force behind the AMCA programme, it would result in a shift from short term tactical thinking to a more long term strategic overview keeping pace with technological developments and future threats.
This presentation on, and an analyses of the AMCA programme to meet the IAF’s requirement of a fifth generation medium weight fighter aircraft, aggregates officially available information on the programme
and attempts to understand the drivers of, and obstacles to, the AMCA.
As seen below, this graph has been collated from official statements on the phasing out and introduction of extant and new combat aircraft of the Indian Air Force. Over the two decades 2012-2032 without querying the feasibility of this induction-retirement schedule, some aspects stand out clearly. The first of these is that the weary MiG-21 will perforce continue to remain in Indian Air Force frontline service well into the 2020s, or close to 60 years of front-line service. Second, specialist aircraft like the Jaguar optimised for ground strike and the air superiority MiG-29 will continue to play a significant role in the Air Force order of battle till at least 2032 with their retirement phase out beginning only in 2027.
The graph shows that the number of front-line fighters is expected to remain well below authorised numbers, assuming that the government will procure another fighter in lieu of the MMRCA programme. Should such a fighter not be procured, and the Rafale procurement remain capped at 36, or should the Fifth Generation Fighter Aircraft (FGFA) being considered for codevelopment with Russia be cancelled, this shortfall will increase dramatically. However, it is important not to merely translate falling numbers with a drop in overall combat capability or effectiveness. In the age of beyond visual range air-toair combat, stand-off precision attack and the ability to strike multiple targets per aircraft per sortie (as opposed to multiple sorties per target some decades back) means that the numeric shortfall does not necessarily mean a shortfall in overall effect or capabilities.
Still, this projection of expected force structure post 2025 will be seen with the MMRCA and Sukhoi Su-30MKI forming the bulk. This means that, contrary to international trends and economics where countries have more lighter (and affordable) fighters and fewer high-end heavy fighters, the Indian Air Force will virtually be almost entirely dominated by twin-engined ‘heavies,’ with their attendant high life cycle and operational costs.
The AMCA programme is envisaged as a replacement of a host of aircraft currently operated by the Indian Air Force and to fill gaps left by retirement of the Dassault Mirage 2000, SEPECAT Jaguar and MiG- 29. The ADA has received definitive design drivers for the AMCA after issue of the Air Staff Requirements (ASR) in 2010.
The broad requirements outlined for the AMCA are for it to incorporate a high degree of stealth, substantial internal and external weapons payload, good internal fuel capacity and the ability to swing from the air-to-air to an air-to ground role. It is also expected to have the capability of supercruise, which allows the aircraft to fly at supersonic speeds without the use of afterburner so providing greater endurance through lower fuel consumption. Even though future air combat is envisaged to be conducted at beyond visual ranges excluding the need for close combat, the AMCA is expected to have a thrust vectoring system which will give it superior manoeuvrability against opponents in the eventuality of an aerial dogfight.
The ADA is designing the AMCA as a platform with high survivability to meet the challenges of future air defence environment through a combination of moderate stealth, electronic warfare capability, sensor fusion and kinetic performance including possible super-manoeuvrability. The design philosophy seeks to balance aerodynamics with stealth capabilities.
The official AMCA layout shown at the lead bears a marked similarity to the F-22 in several aspects of the overall design, and the structural layout of the aircraft incorporates some of the key design features that define a 5th generation fighter aircraft.
ADA indicates a horizontal S-curve for the inlet trunk with the internal weapons bay providing a vertical S-curve of sorts. However, since these are still merely
renderings, one does not know what the extent of the offsetting and hence radar masking of the engine will be. The F/A-18 for example has a partially offset engine and requires the addition of an inlet blocker to mask the engine from incoming radar waves.
The PAK- FA ( Sukhoi T- 50) has a distinctly serpentine duct and significantly more offset engines than the F/ A- 18. However, it has a vertical S-curve, which still does not manage to mask the engines completely, therefore requiring an inlet blocker similar to the F/A-18.
On the other hand as can be seen from the F-22 and the AMCA layouts, both share the use of broad central internal weapons storage just aft of the air intakes. While one can speculate that this combined with the vertical S-curve may mask the engines entirely, it is impossible to tell at this stage given that the dimensions of the engine remain unknown and hence their volumetric and alignment implications are unclear. Moreover, it should be remembered that the F-22 is a large heavy fighter with much space for such expansive configurations. Whether such a configuration will suit a smaller and lighter fighter remains to be seen. It is to be noted that the official drawings only show the internal carriage of air to air weapons, possibly a conscious compromise given the volumetric restrictions of the design, unless India develops munitions similar to the American Small Diameter Bomb (SDB) or obtains US variants for integration with the AMCA.
The following drawing clearly indicates evolution of the AMCA design and is consistent with the several modifications to that design over the years. The initial tailless double engine, delta design is clearly not considered any more.
Despite the obvious similarities with the F-22, note must be made of the front end shaping which seems much closer to the unmanned Boeing X-36 demonstrator than the F- 22. Irrespective, the design shows significantly greater emphasis on allaspect stealth shaping than does the Russian PAK-FA. If current graphics are transferred accurately into production aircraft, a high level of stealth can be expected against radars operating in the L band. X to C band stealth however will be majorly dependent of the quality of construction, the shaping of the facets and of the equipment and weapons bay doors and most importantly, the jointing. The exact nature of the skin’s radar absorbency has not been discussed. It is safe to assume however this will be in the nature of a Radar Absorbent Material (RAM) coating, possibly paint rather than the integrated RAM treatment cured into the F-35’s panels. What kind of treatment will be applied to the joints is unclear, though the possibility of the maintenance intensive ‘adhesive strips’ of the B-2 and F-22 appear likely.
Perhaps the most significant feature that detracts from stealth in these early design phases is the circular engine exhausts. These are not just radar reflective but also erode stealth in the infrared and other electro-optical detection arenas. By way of contrast, square exhausts as on the F-22 reduce infra-red signatures by up to 25 per cent given the 25 per cent increase in surface area of a square over a circle of the same dimensions. The exhausts of the YF-23 combined this approach of squaring out the exhausts, with a long trailing pathway embedded with heat reflecting tiles in the downward section. Cooler air flowing over the top of the aircraft would combine with the hot exhaust in this pathway to further reduce the heat signature. The large tails shield the exhaust troughs from the sides, providing a significantly reduced heat signature across 270 degrees.
There still seems to be a lack of clarity on the size of the weapons bay. The illustrations in this article variously indicate 4 or 5 air-to-air missiles that look exactly like the American AMRAAM. Some indicate the carriage of 4 Russian RVV-AE (AA-12 Adder) missiles, which have a much greater diameter than the AMRAAM that is further increased by the grid-fin control surfaces aft. Others seem to indicate two 1,000 lb indigenous Sudarshan Laser Guided Bombs (LGBs). Interestingly, earlier graphics showing smaller side weapons bays for dogfight missiles exactly mimic the configuration of the F-22’s side bays. Such a large volumetric capacity would therefore also appear to approach the F-22s weapons load of two 1,000 lb Precision Guided Munitions (PGMs) along with two BVRAAMs in the main bay, in addition to two close combat missiles in the side bay. The latest graphics however seem to have eliminated the side bays. There is also an inconsistency with the depth of the bays, the latest drawings demonstrating a loadout of AMRAAMs are clearly not deep enough to hold the much bigger Sudarshan LGB.
Perhaps the biggest design challenge for the AMCA’s weapons bay is the lack of a suite of indigenously produced weapons systems. As of now the beyond visual range Astra and Sudarshan LGB are in their test phases. This means an optimal weapons bay size cannot be arrived at without significantly constraining the size of future weapons developed domestically. This may, in fact, have significant positive effects on future weapons designs by volumetrically limiting their size and prioritising compactness, and miniaturisation.
It is for this reason that the latest official drawings show a single large bay with two bifold doors as opposed to previous graphics that showed a middle ridge separating two distinct weapons bays. The implications for hull integrity however cannot be gauged till the prototypes roll out.
The AMCA will incorporate an active electronically scanned array (AESA) radar and official illustrations clearly seem to indicate additional mechanical steering for the array, along the lines of the Eurofighter Typhoon’s Captor-E radar. This explains the legacy ‘bulge’ of the radome as opposed to the more tapered radomes of other AESAequipped fighters such as the F/A-18E/F Super Hornet and the F-22 Raptor. ADA claims that radome of the AMCA will be of ‘ advanced construction,’ presumably meaning that it will only allow the mated radar’s operating frequencies to transmit to and from, while blocking other frequencies. This is a significant stealth measure since conventional radomes are merely shaped for aerodynamic efficiency but freely allow electromagnetic waves through. This means radar waves ‘see’ past the radome to a flat antenna, which increases the Radar Cross Section (RCS). It remains to be seen if the radar will be acquired from abroad or developed indigenously, given the experience with the indigenous radar for the Tejas LCA.
No mention has been made of radarevading glass for the cockpit canopy, which presents a similar problem as with the radome. Conventional plexiglass allows radar waves into the cockpit, where the internal equipment strongly reflects radar energy. The F-22 solves this problem with a canopy that is counter-intuitively designed to be radar reflective (with a metallic coating) and has a continuous curve structure, minimising the radar return. This ensures that RCS is controlled at the canopy surface and the interior surfaces do not come into play at all.
Present graphics and statements indicate that the AMCA is expected to house most sensors conformally to maximise stealth. What cannot be discerned from these graphics is presence of an electro-optical detection system, either for missile approach warning and general situation awareness, or for air-to-air or air-to-ground detection and targeting. Unlike the F-35 but similar to the F-22, the AMCA does not appear to have a conformal Electro-Optical Targeting System (EOTS), which would seriously hamper its strike capabilities by forcing use of an external pod. While the ADA does indicate that the AMCA will have an IRST, drawings do not show the shape and location of this sensor. Conventional dome-shaped IRST installations such as the OLS-series used on Sukhoi and MiG fighters, and even the F-35’s faceted EOTS, are constructed of artificial leuco-sapphire. Various attempts at tracking down local producers of leuco-sapphires in India have yielded no results, and possibly implies a local production deficit.
The ADA is designing the AMCA with an internal fuel capacity of 4 tonnes to obviate the necessity of carrying wingmounted fuel tanks, which significantly compromise the aircraft’s stealth properties. The ADA estimates that the AMCA will have a combat radius of 1,000 km on these 4 tonnes of internal fuel. It will however be equipped with air- to- air refuelling capability, increasing its endurance and operational radius as can be seen in the range arcs provided alongside. It must be noted that the F-35A carries 8.3 tonnes of fuel and the F-35C close to 9 tonnes, enabling both these aircraft to achieve a combat radius of around 1,100 kilometres at a maximum take-off weight (MTOW) of approximately 31 tonnes. It would seem therefore that the AMCA would have to be half the weight of the F-35 in order to achieve a 1,000-km unrefuelled combat radius or have revolutionary engines that cut fuel consumption in half. Given that the AMCA is a twin-engine aircraft
with greater fuel consumption, the range statistics as given by the ADA simply do not hold up to preliminary scrutiny.
The AMCA programme, unlike the LCA, will be able to leverage experience gained from development projects over the decades. When the LCA programme was sanctioned in the 1980s, India not only lacked the technical wherewithal to develop and build 4th generation fighters, it had not even built a 3rd generation fighter on its own, resulting in a protracted development process, with no relevant institutional knowledge to rely upon.
When the AMCA programme gets underway and moves towards its first technology demonstrator, it will have access to a number of 4th generation aircraft technologies that can be improved upon and employed. Like the LCA, lightweight composite materials are expected to form a high percentage of the AMCA’s construction. Indigenous developments in composite technology, avionics, digital fly- by- wire flight control systems, glass cockpits which reduce pilot work load and some in-counting weapon systems programmes, will have given the AMCA a strong base from which to start its development. On the other hand, India’s failure in aero-engine development will perforce have ADA selecting a foreign vendor for the AMCA’s engine requirements.
Still, the AMCA programme faces a number of practical constraints and the ADA has devised strategies to work around these. As the ADA realises its limitations concerning available manpower and in-house resources, the expertise and resources of the private industry could well be leveraged.
It is envisaged that the AMCA programme will make a clear break from the approach followed in the LCA development and production. Not only will the private sector be embedded as part of the development process, it will also play a major role in production of the aircraft. The aircraft design will be divided into a number of major modules developed and (see image), with each module built independently and undergoing final
assembly by a ‘lead integrator.’ In a novel approach, select private companies will execute construction of each module (see drawing). These modules will conform to laid down design processes and procedures, requiring stringent testing and quality assurance ‘sign off’ before delivery for final assembly.
Presently, state-owned HAL is the only company in India with the experience and technical capacity to play the role of a lead integrator. It is also the only company in the country that has the infrastructure and experience for flight-testing, certification and series production. But given that the AMCA programme will take a decade or more before it is ready for full-scale production, the possibility of private players developing such technical wherewithal to play the role of lead systems integrator cannot be ruled out. Tata’s and Reliance Industries are both in the process of forming collaborations with foreign companies to enter aircraft production. It is therefore imperative that the lead integrator with requisite infrastructure and expertise be identified early enough if ADA plans to overhaul the existing supply chain and production models in place.
The identified agency for integration will be involved early in the design process. While ADA will create a framework for the outsourcing of modules and their integration, the selected agency will be responsible for monitoring companies charged with the construction of different modules, who in turn will be responsible for outsourcing the sub-systems required for the module.
The graphic below is a representation of the work load that the ADA expects to outsource when the AMCA goes into the production phase compared to the current supply chain model in place for the HAL LCA.
As clarified several times by ADA, prime objective of the design phase remains the ‘creation of space.’ This means that given restrictions on weights and dimensions, the size of the weapons bay is to be optimised. At the same time, sensor fusion and stealth characteristics are stated by the ADA as ‘prime drivers’ of the design, which seems to indicate an incomplete understanding of what it is that a fifth generation fighter actually does. To be noted here is the festering problem of systems integration and sub-system size, which are issues that have also dogged the F-35 programme, one which is the product of a mature aerospace industry and already has prior fifth-generation experience to draw upon. Largely as a result of these and associated problems, stop-gap measures have been adopted for the F- 35’ s synthetic vision systems, while weapons bays have shrunk owing to the volume of certain sub-systems. External shaping to maximise stealth has also been compromised, prompting several commentators to reclassify the fighter from the ‘Very Low Observable’ (VLO) category to the ‘Low Observable’ (LO) category.
The lack of several core optical and electronic sub- systems manufacturers, production expertise and end user knowledge and expertise are particularly worrying as several of these will be produced and used for the first time in India. Consequently the potential for each of these to significantly add to time delays, late stage design modifications and the associated massive cost escalation remains immense, albeit any public proposals for concrete risk-reduction measures. In that sense the concept of ‘creating space’ loses meaning unless sub-systems bloat, and mass and volume increases of these sub-systems are not factored in. Of equal concern is the lack of public discussion on expected operational and life cycle costs of this aircraft or specifications from the Indian Air Force as to what the desired price range of such cycles should be.
The second issue is what the term ‘ medium’ really means in the Indian context. Is it a definition based on cost? weight? range? payload? Given that MoD representations to successive parliamentary standing committees on defence have variously blurred the definition of this aspect, the question remains: can India afford a heterogeneous fleet of five different kinds of aircraft, with almost zero commonality across systems, maintenance standards, support infrastructure, and training? There is no clear cost-benefit analysis in the Indian context of the weight-based categorisation of aircraft, given the lack of any document
that publicly states desired effects. It is telling that the F-35 represents the ‘Lo’ end of the USAF’s ‘Hi-Lo’ mix and yet has twice the range of the AMCA. More importantly, the question of what effects the IAF desires from its fleet remains unanswered – even in private discussions ! This is problematic both in the context of the overall fighter force but specifically on the AMCA. This clearly indicates that the AMCA’s design drivers have not been back-calculated based on required effects.
Importantly, while LO and VLO are just one aspect of a fifth generation fighter the most critical aspects are in fact sensor fusion, man- machine interface and the integration of the aircraft with other land sea and air forces and as part of a broader fleet of aircraft comprising a totality of air power. An elaboration of these aspects has been notably absent from the design phases.
While HAL’s move from being prime manufacturer to prime integrator of the AMCA is a laudable shift, several lessons that have been learnt in the Sukhoi and LCA programmes seem to have been ignored. Chief among these is that India faces a shortfall in capacity not just in manufacturing but also systems integration. Most manufacturers in fact consider systems integration to be the hardest, most expensive part of building a weapons system. To complicate matters, not a single Indian university offers a course in systems integration, indicating a significant lack of domain knowledge.
Similarly the openness to foreign manufacturers for local co-production is a laudable goal and indicates a shift in the right direction. The issue is that ADA needs to be investing heavily in a smart team to lobby parliament and policy makers for changes to the Intellectual Property Rights (IPR) and investment laws, as these would abort any useful transfers of technology and processes from these foreign manufacturers.
There are further aspects to consider as well, including the all- important issue of industrialisation. A country that imports and industrialises such high-end technology needs to have broad spectrum amortisation plans to make the costs of technology absorption bearable. This must include active consultation with the private sector for spin-off of technology and scientific knowledge gained into future projects. Unlike the HDW Type 209 submarine procurement, where India gained knowledge but failed to leverage it after the last submarine was built, India must now look towards innovative models such as that in Australia. The building of the Collins- class submarines, for example, saw migration of the highly skilled workforce to the mining sector after the completion of the submarine programme and resulted in the Australian mining revolution with innovative approaches to mineral extraction.
Equally important, given the level of customisation involved for a (so far) single customer, and the consequently expected low production run, the economics of a standalone programme and the willingness of the private sector to invest in this must be examined closely at the embryonic stages.
It might be a good idea for the Aeronautical Development Agency to implement or consider the following before concrete proposals for funding are forwarded to the government: Consolidate and define the exact meaning of the term ‘medium’ in IAF thinking, including clear measures pertaining to range and payload, but more importantly a price range significantly lower than ‘ high,’ and correspondingly lower operational and lifecycle costs. Commence intensive negotiations with the private sector for a joint proposal to the government on: (a) framework of investment and IPR laws to facilitate technology transfers specific to this programme. ( b) comprehensive feasibility study on the capacity of Indian industry, both public and private, to absorb technologies so transferred. (c) costs and knowledge amortisation programme for the private sector. Identification of manufacturers of key sensor and subsystems technology and the data linking and networking and systems integration requirements. This should be followed by clear parameters regarding volume and power consumption. The design of the aircraft should optimally be built around these systems rather than having the systems attempt to conform to a pre-conceived airframe configuration. Have a Public-Private document clearly analysing the possible failure points and the necessary risk reduction measures to be undertaken. Request from ADA to the Indian Air Force to clearly spell out effects rather than capabilities and generate a clear understanding of what the term ‘fifth generation’ really means in our context.