There are three things you should know about the Indian AMCA (Advanced Medium Combat Aircraft) proposal.
1. The project has been halted (see citation below).
2. From the pictures that I've seen, the AMCA airduct looks straight and lacks a S-duct design. Basically, it's not stealthy.
3. The Indian AMCA is a very short aircraft design. If the project is ever restarted and the plane built in the distant future, I don't think there's room for a S-duct.
The Chengdu J-20 is 20.3m in length. The F-22 is 18.9m in length. A 19m or 20m long airplane permits a gradual curve in the S-duct to allow air to flow smoothly during supercruise.
The proposed Indian AMCA is only 13.2m in length. There is not enough length to accommodate an aerodynamic serpentine duct.
----------
Right now, AMCA is vaporware
Tejas grounds Medium Combat Aircraft project | The Sunday Standard
"
Tejas grounds Medium Combat Aircraft project
By NC Bipindra - NEW DELHI
Published: 21st Apr 2013 10:16:44 AM
Troubles in Indias ambitious Light Combat Aircraft (LCA) project has inflicted gaping wounds where it would hurt the Indian Air Force (IAF) the mostthe future plans for an Advanced Medium Combat Aircraft (AMCA).
The Ministry of Defence (MoD) has put on hold the AMCA project that is being spearheaded by Defence Research and Development Organisations (DRDO) Aeronautical Development Agency (ADA).
The reason for the sudden decision to send the AMCA projectwhich began in right earnest in 2006 as the Medium Combat Aircraft (MCA) development in 2006to cold storage is to help ADA to focus all its energies to first work on completing the much-delayed LCA project. The AMCA has been put on hold for the moment. This decision was taken recently to let the ADA focus on the LCA project, top Defence Ministry sources told The Sunday Standard.
The AMCA project, for which the IAF provided the final Air Staff Qualitative Requirements (ASQR) in April 2010, may be taken up at a later date, sources said. But that will still be far away in the future.
India will buy Rafale planes from the French Dassault Aviation as part of its 126 Medium Multi Role Combat Aircraft (MMRCA); in the tender there is a provision to buy another 63 as a follow-on order. That apart, India is working on the Fifth Generation Fighter Aircraft (FGFA) in collaboration with Russia. With the final agreement on the design and development of the FGFA three months away, India will get at least 140 FGFAs for induction by 2027. Considering that most of the capabilities of AMCA will be covered by the MMRCA and FGFA planes, the revival of the AMCA will be a well thought-out one, sources said.
The AMCAs envisaged features include stealth, multi-role operations, adequate precision strike capabilities, including critical first-day missions such as Suppression of Enemy Air Defence (SEAD) and Destruction of Enemy Air Defence (DEAD).
The much-touted Tejas has taken 30 years already, at an escalated project cost of Rs 5,489 crore. Since the LCA project was sanctioned in 1983 at a cost of Rs 560 crore, the time overrun has resulted in a 10-fold increase in the project cost. The plane is yet to get even its Initial Operational Clearance (IOC) so that the IAF could take the plane for a spin. But sources pointed out that the LCA still lacks certain critical capabilities, including a reliable radar, and is deficient in at least 100 technical parameters. The plane cannot fly on its own. It needs a lifeline in the form of support and monitoring of its systems from the ground by technicians, they said.
The LCA, in fact, gave creditable flying displays during the AeroIndia show in Yelahanka in Bangalore in February this year, and followed it up with weapons firing to hit both ground and aerial targets during the Iron Fist fire power display by the IAF in the Rajasthans Pokhran ranges, again in February this year. The common man thinks the plane is doing fine, its engine sounds great and the manoeuvres are perfect. But those flying and weapons firing displays are done with ground monitoring and support. The plane is still not ready to flying on its own, sources stressed. Their guess is the LCA may not meet its schedule of obtaining the IOC before July this year and it could take till December this year or early next year before it is ready. To give an example of LCAs troubles, the sources noted that LCA was grounded for three months between September and December 2012 following problems with its landing gear. Normally, a combat plane is ready for its next sortie following a 30-minute attention from ground service personnel soon after it has returned from a mission. In the case of LCA, after a single sortie of about an hour or so, it needs three days of servicing before it can go for its next sortie, they said.
At present, the IAF has placed an order for 40 LCAs Mk1 to raise two squadrons by 2016-17 with HAL which is the nodal agency for production of Tejas. But these will be delivered with the American General Electric F404 engines which provide only 80 Kilo Newton power.
Later, 80 more LCAs of its Mk2 version will be ordered for raising four more squadrons. The LCA Mk2 will be powered by the GE F414 engines that provide a 90 Kilo Newton thrust."
----------
Indian AMCA lacks S-duct stealth design
Indian AMCA lacks S-duct stealth design. Red arrows show straight airflow.
With the lack of a S-duct design, radar will reflect off of the engine fan blades and the current AMCA will look like a fourth-generation fighter to radar.
Real AMCA doesn't have room for S-duct
In the following diagram for the AMCA, it is clear there is very little room for the airduct and the weapon bay.
AMCA has straight airducts.
In any case, if the AMCA is ever built, I will use real photographs to prove that it has straight airducts.
In this unrealistic Indian cartoon illustration, I can still draw a straight line for a direct radar reflection.
----------
Advanced Medium Combat Aircraft - Wikipedia, the free encyclopedia
"Advanced Medium Combat Aircraft
...
Length: 13.20 m (43 ft 4 in)"