The official CAD images above, from the Advanced Projects & Technologies (AP&T) directorate of India's Aeronautical Development Agency (ADA) provide further perspective on the low-observable design elements that are known to be going into India's Advanced Medium Combat Aircraft (AMCA), known for a while now to be a stealth aircraft concept. Serpentine air intakes (with minimum flow distortion and robust pressure recovery) and internal weapons bays, depicted in the images above, are some of the most critical nose-on low observability design elements going into the programme.
As part of the multidisciplinary design optimization (MDO) currently on for the AMCA -- a wind tunnel model of which was first publicly displayed at AeroIndia 2009 -- that design-based stealth features will include further optimized airframe shaping, edge matching, body conforming antennae and a low IR signature through nozzle design, engine bay cooling and work on reduced exhaust temperature. RAMs, RAPs, special coatings for polycarbonate canopy and precision manufacturing will all be part of the effort to make the AMCA India's first stealth airplane.
With aerodynamic design optimisation near complete, the AMCA's broad specifications are final. The aicraft will have a weight of 16-18 tons [16-18 tons with 2-tons of internal weapons and 4-tons of internal fuel with a combat ceiling of 15-km, max speed of 1.8-Mach at 11-km. The AMCA will be powered by 2 x 90KN engines with vectored nozzles. For the record, the official ADA document that will finally be processed this year by the government towards formal project launch describes the AMCA as a "multirole combat aircraft for air superiority, point air defence, deep penetration/strike, special missions".
An earlier post on the AMCA is here.