February 01, 2012 : With the amount of energy and focus the government has invested, and continues to invest, in the Light Combat Aircraft (LCA) programme, some crucial evolutionary efforts get blindsided. Of particular interest is the Advanced Medium Combat Aircraft (AMCA), a stealthy fifth generation manned fighter concept intended to produce a potent multirole platform (with a focus on strike profiles) that will, in time, supplant the Indian Air Force's Jaguars and MiG-27s. The government prefers that the AMCA project, headed by scientist Dr A.K. Ghosh, remains below the proverbial radar, but the secrecy with which the effort progresses has led many to wonder if the AMCA could actually be India's final indigenous manned fighter aircraft programme. (The question assumes huge importance considering that full scale engineering development (FSED) of the platform could begin within a year.) That notion is supported by to facts: one, the aeronautical establishment will be investing majorly in unmanned combat aerial vehicles (specifically the Predator-like Rustom-H and stealthy flying wing AURA) going with doctrinue, and two, the fighter types that will be inducted in the next decade -- both Indian and foreign -- will be templates for improved variants that could be in use for at least the next half-century.
For now, however, the AMCA is a well-defined programme that looks to deliver tangible results in terms of a credible, potent combat aircraft platform on the lines of the Lockheed-Martin F-35 Lightning-II. It makes sense, therefore, for the Indian military-industrial complex to develop evolutionary technologies that will find place both on manned and unmanned platforms. On the AMCA, Indian scientists are looking to push the envelope further than they've ever tried to before. Every little bit makes a difference when a legacy leap is at play, which is why, from engine performance parameters to control surfaces to control laws to cockpit ergonomics, everything is up for change.
The obvious evolutions are clear: low-observable shape and airframe materials, extensive use of carbon composites, internal weapons bays, low bypass low-emmission engines, modular internals etc. The deeper you go, the more complicated and revolutionary the plans actually become.
If AMCA project director Dr Ghosh meets his objectives, then one of the most compelling aspects of the AMCA will be its cockpit and man-machine interface. To begin with, unlike the decidedly crowded, fourth-generation cockpit of the LCA Tejas, the AMCA cockpit is being developed with a panoramic active-matrix display, of the kind available on American fifth generation aircraft. Switches, bezels and keypads stand to be replaced with touch screen interfaces and voice commands. What Dr Ghosh's team wants is for the future IAF pilot to have a helmet-mounted display system that allows the dispensing of a head-up display (HUD) from the cockpit altogether, a revolutionary concept. The Aeronautical Development Establishment (ADA), which oversees the AMCA programme, has asked private industry in the country to explore the feasibility of creating primary panoramic displays and other avionics displays that would befit a fifth generation cockpit environment. The cockpit, however, is simply one of what is a hugely ambitious technology wishlist that Dr Ghosh and his team are pinning their hopes on for the aircraft they ultimately produce.
The proposed evolutions begin at the lowest level -- system architecture -- and will attempt to build a triplex fly-by-light electro-optic architecture with fiber optic links for signal and data communications, unlike the electrical links on the Tejas platform. Significantly, unlike centralized architecture on the Tejas, the AMCA proposes to sport a distributed architecture with smart sub-systems. Likewise, unlike the LCA's centralised digital flight control computer (DFCC), the AMCA is likely to have a distributed system with smart remote units for data communication with sensors and actuators, a system that will almost definitely require much faster on-board processors.
Sensors will be a proving ground for just how advanced the AMCA programme is, and will be in reality a test case for future applications on unmanned vehicles. Scientists will be working towards getting the mechanical gyros and accelerometers, standard on the Tejas, to evolve on the AMCA into fiber optic gyros, ring laser gyros and MEMS gyros. The pressure probes and vanes that make up the air-data sensors will become an optical and flush air data system, and position sensors will be linear/rotary optical encoders. Importantly, actuators -- currently electro-hydraulic/direct drive -- could be electro-hydrostatic to accrue substantive weight savings on the AMCA. Sensor fusion for an overarching situation picture is something the ADA is already attempting to achieve on the Tejas suite, so one the AMCA it should be a standard requirement.
One of the key areas that India has lagged behind on is control laws. The AMCA should feature highly evolved integrated control laws for flight, propulsion, braking, nose wheel steer and fuel management and adaptive neural networks for fault detection, identification and control law reconfiguration. All of this will cost the country much, but will find valuable applications in the unmanned programmes, particularly AURA. Unlike the Tejas, which features an avionics systems architecture based on functionality-based individual computer systems connected on MIL-STD-1553B buses and RS 422 links, the AMCA's avionics systems architecture, it is hoped, will feature a "central computational system connected internally and externally on an optic fiber channel by means of multiport connectivity switching modules". In such a system, functionality will be mapped on resources optimally and reallocated when faults occur. Data communications on the AMCA's processing modules will be through a high-speed fiber channel bus, IEEE-1394B-STD. The connectivities will be switched by means of a multiport switching matrix, with data speeds of 400MB/second. In literature made available on the programme, these facets reveal the stunning leap scientists are looking to make with this one manned aircraft programme.
The AMCA is almost certain to have integrated radio naviation systems, where all burdens earlier borne by analogue circuits will be carried out by digital processors. Communication systems will be based on software radio ranging from UHF to K band, with data links for digital data/voice data and video.
One of the most exciting new area being exploited for the AMCA is algorithms. While the LCA suite no major decision aid to the pilot, the AMCA commander will have the ability to plan attack strategies, avoidance tactics, retreat strategies and evasive strategies for himself and his partners in the air. Each of these technologies, planned in a manned environment are being evolved and developed for extension to an autonomous unmanned environment as well. Critics would argue that the establishment needs to focus on finishing what it has started before dreaming big. Others would say, it's better to think big now, than face repeated obsolescence even before your bird flies.