With India’s 5th Generation Stealth AMCA Program all set to go critical from next year with the official monetary sanction for the funding for the program, ADA has revealed further changes to the design aspects of the final AMCA design which is likely to be frozen soon and will now feature Diverterless Supersonic Inlet (DSI) which were not shown in the previous mock models displayed in various defense exhibition in the country . While was first to show DSI equipped Computer-Aided Design (CAD) image of the AMCA with DSI inlet in its previous reports it was not confirmed if it will make it to the final AMCA design at that time.

Scaled Models displayed of the AMCA by ADA in last few months also featured 2D Ramped intake but switch to the 3D Diverterless Supersonic Inlet (DSI) has been under works for some time now and after design refinements and wind tunnel testing it has been cleared to be featured from the first Technology Demonstrator (TD)-1 onwards.

AMCA will also have a serpentine air intake to further improve stealth and design elements of the aircraft after the addition of the Diverterless Supersonic Inlet (DSI) in the AMCA design it will have ability to drastically reduce the aircraft’s radar cross-section since research has shown that the traditional intakes are potentially large sources of radar return.

Another advantage of using Diverterless Supersonic Inlet (DSI) is that the DSI technology will reduce the amount of radar-absorbent materials needed for each aircraft especially on the frontal side of the aircraft where Radar cross-section needs to be at its best to reduce detection. DSI inlet also has the potential of delivering better engine performance at supersonic speeds, without added weight and mechanisms.


AMCA Scaled Model Displayed Showcased Previously had Air Intakes which Were Separated From the Body Of the Aircraft

A reliable source close to has now confirmed that since ADA has decided to move to Diverterless Supersonic Inlet (DSI) and from the 2D Ramped intake featured in the previous design then the aircraft will also need to feature additional design changes to incorporate DSI inlet. 

  • To make DSI inlet work more effectively and to further reduce its signature, AMCA will now have to feature a three-dimensional (3-D) bump on the aircraft body near the entrance of the DSI inlet (ex as seen in Chinese J-20) so that it acts as an obstruction to further conceal engine’s exposure to radar. (see Pic 1 and above pic of AMCA DSI )
  • In previous AMCA design, air intakes were separated from the body of the aircraft as also seen in American F-22 intake design but with DSI inlet this will go and it will be more integrated to the body of the aircraft. (see Pic 2)

Pic 1 J-20 DSI Inlet with 3D Bump 

Pic 2 F-22 Air Intake separated from the main aircraft body 

DSI inlet R&D 

ADA first started experimented with DSI technology for the LCA-Tejas Mk1 and Mk1A fighter aircraft design but it was never implemented due to freezing of the design before the completion of the research and development on the DSI technology. CAD simulation on the Mk1 design was used to further understanding of the DSI technology and it was implemented on the AMCA design has well but was never displayed in scaled models

Additional features in Final design 

Another additional major design improvements which we may see soon in the final AMCA design will be the addition of the 3D thrust vectoring nozzle to the engines which ADA will design with Russian manufacturer. Plug and fit 3D thrust vectoring nozzle in development can be installed in any engine of foreign origin which ADA will procure for the AMCA program.

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