India has unveiled an updated design for its so-called fifth-generation fighter concept, known as the Advanced Medium Combat Aircraft (AMCA).

Representations of the fighter have changed often in the last few years. But the 1:8-scale model of the concept displayed at last month's Aero India 2013 show in Bengaluru is the final configuration and the one with which the program will proceed.

The twin-engine, stealthy, multirole fighter was first unveiled at the Aero India show in 2009, in the form of a metal wind-tunnel model. At the show in 2011, a reshaped model revealed an F-22-like appearance.

The final design, or at least the one the concept designers have put out this year, is strongly reminiscent of the Northrop Grumman YF-23 prototype that lost the Advanced Tactical Fighter competition to the Lockheed YF-22 in 1991 in what became the F-22 program.

The AMCA's new fuselage is stretched, with symmetric trapezoidal wings, notably losing the leading-edge extensions that were once part of the design. The aircraft will have an internal weapons bay and fully indigenous stealth technologies now under development, including radar-absorbent paint and composites.

That is the plan, at any rate. With the country's Tejas Light Combat Aircraft (LCA) program increasingly adrift ahead of a 2015 squadron service target, there has been skepticism within the Indian air force about the pragmatism of committing resources toward an indigenous fifth-generation platform, especially when more than $10 billion will soon be committed to the Hindustan Aeronautics Ltd. (HAL)-Sukhoi T-50-based fighter program. But those concerns have not stood in the way of resources and funding flowing into the AMCA program and an elaborate wish list of technologies being lined up to define an aircraft that almost certainly will not see a first flight before the next decade.

“Let's be clear: the HAL-Sukhoi program isn't a joint effort,” says an air force officer with Bengaluru-based Training Command. “The airframe will be identical to the ones the Russians currently have in flight-test. Our decision to go with a single-seat configuration is principally to avoid potential time overruns that will almost certainly be part of designing such a configuration. The maximum that HAL will do is insert a few systems of our choice and play lead integrator for the 'MKI,' if you will,” he says, alluding to the MKI version of the two-seat Su-30 developed by Sukhoi for India.

“Therefore, it is imperative that India look ahead and begin developing technologies and platforms like the AMCA,” the officer adds. “We cannot forever be a buyer of aircraft that are conceptualized, designed by others and simply assembled or license-built here.”

A senior scientist at the AMCA directorate in Bengaluru says, “we have the fourth-generation Tejas on the one hand. But evolutionary technologies we are developing for the AMCA are on the cutting edge. They hope to be comparable with the best in the world. If we need a little help along the way, in the interests of pragmatism, cost and time, we will study the feasibility of cooperation. But this ideally needs to be a fully Indian program. Sensitive stealth technologies will not be shared by foreign technology companies.”

A brief list of the ambitious technologies with which India's Aeronautical Development Agency (ADA) hopes to equip the AMCA includes a panoramic active-matrix cockpit display, triplex fly-by-light architecture with an optical-fiber-based digital flight-control computer, and serpentine air intakes to suppress radar signature.

Describing the AMCA as a “fifth-generation-plus” platform, Defense Research and Development Organization chief Vijay Saraswat says that “work on the AMCA will begin soon. This will involve identifying technologies and systems for the aircraft.”

Saraswat has also appealed to Indian private-sector companies to support and get involved in the program. Industry executives indicate that aircraft makers including Saab, Dassault and EADS have expressed a willingness to consult with the ADA on the AMCA concept to speed things along. A formal selection of possible foreign technologies could happen this year.