Friday, December 23, 2011

India's 5th Gen Advanced Medium Combat Aircraft

Evolutionary Technologies for India's 5th Generation 
Advanced Medium Combat Aircraft

Wind Tunnel Test Models

Conceptual Model

If the specialised team led by Indian aerospace scientist Dr AK Ghosh achieves what it has set out to (a huge IF, with all due respect), then one of the most dramatic aspects of India's concept fifth generation Advanced Medium Combat Aircraft (AMCA) will be its cockpit and man-machine interface. For starters, unlike the cluttered, resoundingly less-than-fourth-generation cockpit of the Light Combat Aircraft (LCA Tejas), the AMCA cockpit could have a panoramic active-matrix display. Next, switches, bezels and keypads could be replaced with touch screen inte
rfaces and voice commands. Finally, what the team wants is for the AMCA pilot to have a helmet-mounted display system that allows the jettisoning of a HUD from the AMCA cockpit altogether. Some pretty hardcore stuff. But the idea is this -- if India is building its own fifth generation fighter aircraft (not to be confused with the Indo-Russian FGFA/PAK-FA), and believes it can deliver, then aim for the damn stars. I've got my hands on AMCA documents that provide the first detailed view of just how ambitious the programme actually is. Let me run you through some of them.

The AMCA team has already 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. But the cockpit is just one of an ambitious official technology wishlist for the AMCA.

The envisaged changes begin at the very basic -- system architecture -- and look towards a triplex fly-b
y-light electro-optic architecture with fiber optic links for signal and data communications, unlike the electric links on the Tejas platform. And unlike centralized architecture on the Tejas, the AMCA proposes to sport a distributed architecture with smart sub-systems. Similarly, unlike the LCA's centralised digital flight control computer (DFCC), the AMCA could have a distributed system with smart remote units for data communication with sensors and actuators, a system that will necessitate much faster on-board processors.

Next come sensors. The mechanical gyros and accelerometers on the Tejas will need 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 evolve into an optical and flush air data system, and position sensors will be linear/rotary optical encoders. Significantly, 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 goes without saying.

The AMCA could 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.

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 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 resourcred optimally and reallocated when faults occur. At least, that's the idea. 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.

The AMCA could have integrated radio naviation systems, where all functions earlier done by analogue circuits will be shifted onto the shoulders of digital processors. Communication system will be based on software radio ranging from UHF to K band, with data links for digital data/voice data and video.

Algorithms will evolve substantially too. While the Tejas features almost no decision aid, the AMCA pilot could have at his command the ability to plan attack strategies, avoid strategies, retreat strategies and evasive strategies for himself and his buddies. Limited fault recording and limited coverage in the maintenance and diagnostics algorithms on the LCA will evolve into far more advanced ones allowing extensive coverage.

This is an official technology wishlist for the AMCA. If it sounds far-fetched and overreaching -- and it well may -- it still provides a glimpse into what the programme is looking at for what will undoubtedly be India's most ambitious indigenous aerospace venture. Before I forget, here's a nice little slide illustrating the AMCA's envisaged operational envelope.

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