HAL AMCA

The AMCA program evolved out of the Medium Combat Aircraft (MCA) programme, was initiated to fulfil several requirements for a common fighter to replace different types of existing fighters aircraft which included Dassault Mirage 2000 and SEPECAT Jaguar. In October 2008, the Indian Air Force asked the ADA to prepare a detailed project report on the development of an MCA incorporating stealth features.[14]

In February 2009, ADA director PS Subramanyam said at an Aero-India 2009 seminar that they were working closely with the Indian Air Force to develop a Medium Combat Aircraft. He added that according to the specification provided by the Indian Air Force, it would likely be a 20-ton aircraft and would be powered by two GTX Kaveri engines.[16]

In March 2010, the aircraft was renamed as Advanced Medium Combat Aircraft (AMCA). In April 2010, the Indian Air Force Chief of Air Staff issued the Air Staff requirements (ASR) for the AMCA, which placed the aircraft in the 25-ton category.[4][17][18] The first flight test of the prototype aircraft was scheduled to take place by 2017 however was delayed eventually.[19] Backing the project, chief of Indian air staff, RKS Bhadauria in a briefing in October 2019 said DRDO "must" make the project happen. Indian Air Force wants to have "full control" in "defining" technologies of aircraft and supports indigenous fifth generation fighter aircraft as it becomes restricted for IAF when purchasing a foreign system.[10]

In October 2010, the Indian Government released ₹100 crore to prepare feasibility studies in 18 months.[20] In November 2010, the ADA sought ₹9,000 crore (approximately €1.5 billion/US$2 billion) of funding for the development of the AMCA.[19] The funding would be utilised to develop two technology demonstrators and seven prototypes.[21] The initial development cost is estimated to be between ₹4,000–5,000 crores to build 3 to 4 flying prototypes.[22][23] Defence ministry has been looking for cabinet approval and funds as of 2019 for prototype development phase which will require ₹7,000-8,000 crores in a decade.[6] Program is slated to be a public-private partnership as of 2020 for development as well as production.[24]

The conceptual design of AMCA was carried out till 2015, at which point the general configuration was frozen.[25] Ten design proposals were evaluated with five designs emerging after intensive wind tunnel testing.[4] Proposal of design which included tail were designated with the serial number 3B-01 to 3B-09.[4] The aircraft was reported to be under Detailed Design Phase in February 2019[1] and design phase expected to be completed by end of 2019.[5] ADA in consultation with the IAF will try to freeze the design of AMCA by June 2020 with first flight planned for 2024.[26]

The initial design of the AMCA was a tailless, delta wing aircraft with twin engines.[4] The design was changed to include horizontal and vertical stabilizers in design 38–01. It featured a double delta wing configuration, that was altered in design 38-09 similar to the F-22.[4]

A cancelled wind tunnel model of Medium Combat Aircraft

AMCA's second design proposal was first showcased at Aero India 2009.[27] The design-based stealth features were further optimized by the use of airframe shaping, composite material, edge matching fuselage, RAPs, body conforming antennae and engine bay cooling, RAMs, weapons bay, special coatings for poly-carbonate canopy and other stealth features, the aircraft had a weight of 16–18 tonnes with 2-tonnes of internal weapons and four-tonnes of internal fuel with a combat ceiling of 15-km, max speed of 1.8-Mach at 11-km.[28]

The aircraft concept was finalized and shown to the Indian Air Force in 2012, after which full-scale development on the project was started.[29] In February 2013, the ADA unveiled a 1:8 scale model at Aero India 2013, to show the finalized proposal.[30][31][32][33]

Project Definition commenced from February 2013 to March 2014, started immediately after the design was finalized with intensive development on the finalised design.[34] [35]

In April 2013, the Ministry of Defence had put the project on hold, wanting to make up for the protracted delays incurred by the ADA and DRDO's labs and establishments during the development of the HAL Tejas.[36][37] According to the Defence of Ministry, "this decision was taken recently to let the ADA and DRDO's Labs to focus on the HAL Tejas."[36][38][39] The AMCA design team led by Mr. A K Saxena had completed low-speed wind tunnel testing, supersonic wind tunnel testing and Radar Cross-Section (RCS) testing between 2008 and 2014 during which all the five design proposals underwent intensive air flow testing, design development and improvements.[40][41]

Design research and development of the finalized design was completed by NAL from October 2012 to September 2014. The R&D efforts led to the current configuration of the aircraft and a structurally efficient wings layout with four bending attachment brackets and two shear attachment brackets. For the AMCA, structural design, analysis and size optimization was carried out to cater for all critical symmetric and un-symmetric load cases. Finite element models were built separately for each of the fuselage segments and then integrated to build a full fuselage finite element model which also incorporated a new design for the air intakes, a key element to maintain the aircraft's stealth characteristics.[42] Project definition phase was fully completed by February 2014.[43]

The Engineering Technology & Manufacturing Development (ETMD) phase was started on 7 January 2014 when work on AMCA had again commenced after HAL Tejas attained IOC, and it was announced that the AMCA will be developed by 2018.[30][44][45][46] The configuration was finalised in 2014, with the first flight scheduled for 2018.[47][48][49][50] The product design work of the AMCA was started by the DRDO and the work on the prototype as the part of proof of concept stage was expected to be ready in 2018.

On 7 February 2014 DRDO Director Dr Tamilmani told reporters on the sidelines of the three-day international meet on Product Life Cycle Modelling, Simulation and Synthesis (PLMSS) at VIT university,’ he said the aircraft would be equipped with twin engines with supercruise power and for the first time it would be using the stealth technology to 'hide' from radar surveillance.[51] At a seminar ahead of the Aero India show, DRDO's chairman Dr. V.K Saraswat said that Indian private sector firms are also participating and offering support in the program.[52]

At Aero India 2015, Tamilmani confirmed that the work on three major technological issues which includes Thrust Vectoring and supercruising engine, AESA radar and stealth technology is going on full swing and availability of the technology on the aircraft will occur on schedule.[53] In 2015, 700 ADA employees were working on the project along with 2,000 employees of DRDO and 1,000 employees of HAL supported by over 500 employees of subcontractors of both Indian and foreign firms. On 7 March 2015 a Memorandum of Understanding (MoU) through Government to Government (G-to-G) route between India and Russia was signed in which various Russian firms agreed to help Indian firms in various technological fields which included the Gas Turbine Research Establishment (GTRE) entered in a joint-venture with Klimov for the development of Three-Dimensional Thrust Vectoring (TDTVC), Electronics and Radar Development Establishment (LRDE) with Tikhomirov Scientific Research Institute of Instrument Design (TSRIID) for the AESA Radar and ADA with the Sukhoi for stealth technology and other various key technological fields.[54][55] In March 2015 Boeing and Lockheed Martin offered to help HAL and DRDO in the field of stealth, thrust vectoring and other key technologies.[56] Work on various technologies was carried out by multiple establishments of DRDO, ADA and HAL which included stealth, engine, three-dimensional thrust vectoring, AESA radar, internal weapons bay, serpentine air intakes and all other major avionics.[40][57][58][59][60] According to Deputy Air Marshall Sinha "To provide adequate time to Indian industries to develop required capabilities, the armed forces will soon come out with a list of technologies of interest... underlining that these efforts are expected to synergise indigenous development of advanced aerospace systems."[61] Saab AB made an offer for participating in the programme on its own and also helping and sharing many technical information and data for development in the AMCA programme.[62][63] Saab's head of aeronautics division Ulf Nilsson, pushed the idea of Saab taking part in the programme. [64][65]

Engine development on K 9 and K 10 started in August 2012 by GTRE. A tender of joint venture on development of the engine was issued to engine manufacturers in 2015 for a foreign partner to help in developing the engine by combining both Kaveri engine technology with the joint-venture partners engine to create a 110–125 KTN thrust engine. On 19 February 2015 at Aero India 2015 Tamilmani told reporters that a tender of joint venture on development of the engine was issued to General Electric, Rolls Royce, Snecma, Eurojet, NPO Saturn to use current engine technology by combining Kaveri engine technology with JV engine to produce an engine capable of producing thrust of 110–125 kN.[66][67][68][69] Tamilmani confirmed the possibility of combining Kabini Core-engine with joint venture partner core engine i.e. with the EJ 200, Snecma M88, NPO Saturn AL-31-117 or General Electric F414 to produce 110–125 KN of thrust. France made an unsolicited call to help in development of AMCA's engine with full access to the Snecma M88 engine and other key technology, while United States has offered full collaboration in the engine development with full access to the GE F-414 and F-135.[70][71] During U.S President Barack Obama's visit on 25–27 January he pointed out a possibility of joint-development of a Hot-Engine, an advanced variable cycle engine capable of performing in hot weather conditions like those of India.[72] Rolls-Royce was also pushing a deal for a joint venture engine by offering the co-development of a new engine based on the Kaveri and EJ2XX engines. In November, during the visit of Indian Prime Minister Narendra Modi to UK, Rolls-Royce again pushed the EJ2XX engine in a joint development proposal despite favouritism towards General Electric for a JV programme. In December U.S government made sign of support for full fledge transfer of technology including many classified information of F-414 engine in joint venture engine development.[73][74][75] During Indian defence minister Manohar Parrikar's visit to the United States, the U.S defence secretary Ash Carter and Parrikar discussed the matter of joint development of the engine.[76][77] Reports emerged in 2019 suggested that initial two squadrons of AMCA dubbed as Mark I are expected to use 98 kN General Electric F414 while next 5-6 squadrons, variant dubbed as Mark II, will use a 110 kN class that will be developed indigenously with a foreign partner.[6]

AMCA uses a modular approach in its design, development and production. Most of the assembly and equipment are outsourced to both private firms and public sector undertakings. A consortium of more than 140 firms are taking part in the programme. This is a major departure from HAL's previous fighter aircraft, the HAL Tejas, which used in-house production with minor outsourcing. Additionally, AMCA uses a modular method of production in order to reduce the time required for development and production. This method of production also results in increased on-schedule delivery resulting in an increased rate of production. Firms participating in the programme include HAL as the prime contractor, while sub assembly is carried out by Tata Advanced Systems, Reliance Aerospace, Larsen & Toubro, and Godrej Aerospace.[4] Sub-assembly carried out by sub-contractors includes the wings, tail, tail fins, raydome, rear fuselage and landing gear.[4]

The development and production of the aircraft is carried out by four types of firm:

• Design team – ADA as the prime designer and developer of the aircraft.
• Core team – DRDO agencies carrying out primary development.
• External agencies – Various institutes, universities and other firms of both domestic and foreign origin.
• Manufacturing team – Manufacturers and assemblers.[4]

Defence Minister Nirmala Sitharaman on April 4, 2018 while answering a written reply in Lok Sabha summer Session said the feasibility study of the project had already been completed and given go ahead by the Indian Air Force (IAF) to the relevant agencies associated with the programme led by Aeronautical Development Agency (ADA) and Defence Research and Development Organisation (DRDO) to initiate AMCA Technology Demonstration Phase before launching full Scale engineering development phase[79] Two technology demonstrator and four prototype are scheduled to go under various type of testing, analysis and development during Testing Phase in January 2019, .[80][81][82]

As of 2019, defense ministry has been seeking approval from Cabinet Committee on Security (CCS) to go ahead with the Prototype Development Phase.[6]

The AMCA is a multirole fighter aircraft, with shoulder mounted diamond shaped trapezoidal wings, a profile with substantial area-ruling to reduce drag at transonic speeds, and an all-moving Canard-Vertical V-tail with large fuselage mounted Tail-wing.[4] Flight control surfaces include leading and trailing-edge flaps, ailerons, rudders on the canted vertical stabilizers, and all-moving tailplanes; these surfaces also serve as Air brakes. The cockpit features a single seat configuration which is placed high, near the air intakes and wings of the aircraft to provide good visibility to the pilot with a single bubble canopy construction.[4] The aircraft features a tricycle landing gear configuration with a nose landing gear leg and two main landing gear legs. The weapons bay is placed on the underside of the fuselage between the nose and main landing gear. The AMCA is designed to produce a very small radar cross-section, to accomplish this it features serpentine shaped air-intakes to reduce radar exposure to the fan blade which increases stealth, uses an internal weapons bay and features the use of composites and other materials.[4] The flight control surfaces are controlled by a central management computer system. Raising the wing flaps and ailerons on one side and lowering them on the other provides roll.

A leading-edge root extension (LERX), which is a small fillet, is situated on the front section of the intake and wings of the aircraft. It has a typically roughly rectangular shape, running forward from the leading edge of the wing root to a point along the fuselage. Also, the AMCA has an In-flight refueling (IFR) probe that retracts beside the cockpit during normal operation.[4]

The AMCA will be capable of operating in manned as well as in unmanned modes.[83] According to the Indian Air Force chief Rakesh Bhadauria, the AMCA will have “sixth generation characteristics”.[3] He later said that such characteristics will added after first focusing on fifth-generation capabilities.[84]

Advance Multirole Combat Aircraft

Stressed ducts in s-shape are locked with airframe with the loaded bulkheads which are made of composite materials spanning the aircraft from air intake to engine shafts.[4] The radome which holds radar is made of advance composite and construction, which result in allowing only the operating frequencies of the mated radar to transmit from the dome, while blocking other radars.[4]

Since the AMCA is a relaxed static stability design, it is equipped with a quadruplex digital fly-by-optics flight control system to ease pilot handling. The AMCA's aerodynamic configuration is based on a diamond shaped trapezoidal-wing layout with shoulder-mounted wings. Its control surfaces are electro hydraulically actuated and digitally controlled using fiber-optic cables. The wing's outer leading edge incorporates three-section slats, while the inboard sections have additional slats to generate vortex lift over the inner wing and high-energy air-flow along the tail fin to enhance high-angle of attack stability and prevent departure from controlled flight. The wing trailing edge is occupied by two-segmented elevons to provide pitch and roll control. The only empennage-mounted control surfaces are the Pelikan tail with single-piece rudder which includes two airbrakes located in the upper rear part of the Pelikan tail, one each on either side of the tail. The AMCA feature a highly evolved integrated control laws for flight, propulsion, braking, nose-wheel steering and fuel management and adaptive neural networks for fault detection, identification and control law reconfiguration.[85] Flights controls of the aircraft are both highly integrated and independent of each other which includes flight controls, engine controls, brake and landing controls, and other systems this is possible due to the active controls gears systems (ACGS).[4]

The digital FBW system of the aircraft employs an advance next-generation distributed digital flight control computer (DDFCC) made by ADE comprising four computing channels, each with its own independent power supply and all housed in differently placed LRU.[86] The DFCC receives signals from a variety of sensors and pilot control stick inputs, and processes these through the appropriate channels to excite and control the elevons, rudder and leading edge slat hydraulic actuators. DFCC provides raising the wing flaps and ailerons on one side and lowering them on the other provided roll. The Pelikan-tail fins are angled at 27 degrees from the vertical. Pitch is mainly provided by rotating these pelikan-tail fins in opposite directions so their front edges moved together or apart. Yaw is primarily supplied by rotating the tail fins in the same direction. The AMCA is designed for superior high Angle of attack (AoA) performance. Deflecting the wing flaps down and ailerons up on both sides simultaneously provided for Aerodynamic braking.[4]

AMCA is a twin-engined aircraft which is powered by two GTRE K 9 + or K 10 engine which are successors to the GTRE Kaveri engine.[87] The K 10 Program is a joint venture partnership with a foreign engine manufacturer. K 10 program engine will be final production standard Kaveri engine and shall have less weight and more reheat thrust along with certain other changes to meet the original design intent.[88] Both the engines are designed by ADA and developed by GTRE.[11] Full scale development of the K 9 and K 10 engine would be completed by 2019.[55] while AMCA Test Demonstrator would be powered by an existing 90 kN thrust engine.[72]

[89] The AMCA will feature geometric stealth and will initially fly with two GE-414 engines. It will be replaced with an indigenous power plant once developed.

The K 9 + and K 10 engines are designed to supercruise with a speed of Mach 1.82 with both engines.[4][90] As of 7 February 2020, DRDO and Rolls Royce are jointly developing an engine which would be based on the Eurojet EJ200 afterburning turbofan, this engine would be placed in the Advanced Medium Combat Aircraft. The engine is expected to produce 110 KN of thrust.[91] The deal is expected to be signed soon.

The AMCA is designed to be difficult to detect by radar and other electronic measures due to various features to reduce radar cross-section include airframe shaping such as planform alignment of edges, fixed-geometry serpentine inlets that prevent line-of-sight of the engine faces from any exterior view, use of radar-absorbent material (RAM), and attention to detail such as hinges and pilot helmets that could provide a radar return. Efforts have been made to minimise radio emissions and both the infrared signature and acoustic signature as well as reduced visibility to the naked eye.[92] Alignment of wings, tail, flaps and other edges increases radar and visually stealthe.[4] The AMCA will also feature a Diverterless Supersonic Intake, which will help improve its stealth capabilities.[83]

Radar absorbing structures and radome, body conformal antennae surface hard aperture, flush air data sensors and frequency selective surface (FSS) radome are used to reduce radar detection.[93] Stealth ability is enhanced by the use of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) during the construction of the airframe and in the airframe and instruments.[4] AMCA's design prevents detection of the aircraft from L band, C band and X band radars.[4] The aircraft's thrust vectoring nozzle reduces infrared emissions to mitigate the threat of infrared homing surface-to-air or air-to-air missiles. Additional measures to reduce the infrared signature include special paint and active cooling of leading edges to manage the heat build up from supersonic flight.

Astra BVRAAM

The AMCA features an internal weapons bay, but a non-stealthy version with external pylons is also planned.[25] The aircraft is planned to be equipped with beyond visual range missiles, close combat missiles, standoff weapons, precision weapons and laser guided bombs.[94] Directed energy weapons are also planned to be equipped on the AMCA.[95]

The aircraft's avionics suite will have IRST and advance situational oriented electronic warfare systems and all aspect radar warning receiver (RWR), Self-Protection Jammer(SPJ), CMOS, laser warning receiver (LWR), missile warning suite.[96]

IRST (Infrared search and track)

Defence Electronics Application Laboratory (DEAL) has designed and developed a next-generation network-centric aircraft management system (including weapons) including various features such as data fusion, Cooperative Engagement Capability, decision aids, integrated modular avionics, and intern signature control with sharpening for low observability.[4][97] The aircraft will use integrated modular avionics for real time computing, and the fiber optic cables used on the aircraft feature photonic crystal fibres technology for faster exchange of data and information.[60] Unlike the HAL's previous fighter aircraft, the Tejas, which has a digital flight-control computer and hydraulic controllers, the AMCA has a distributed processing system employing fast processors and smart subsystems and will be electronically controlled via a "central computational system connected internally and externally on an optic-fiber channel by means of a multi-port connectivity switching module". This results in using the IEEE-1394B-STD a departure from MIL-STD-1553B data-bus standard.[98]

AMCA would be equipped with a variant of the Uttam AESA Radar mounted on a mechanically steerable mount.[4] An onboard condition monitoring system is planned to be included in the AMCA.[99]

The AMCA's cockpit features a panoramic active-matrix display, with the switches, bezels and keypads replaced with a single large multi-functional touch screen interface supported by voice commands (Also the cockpit will be fully made by composite or glass).[85]