Source: INDRA
Stealth Capabilities of LCA-Tejas :-
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With many claims of Tejas possessing some degree of Stealth, it was necessary to analyze at how much degree does Tejas really possess stealth. To begin with Tejas has a Radar Cross Section of 0.5 meter square ( public available figure ) which is among the lowest in 4th Generation Fighter Class. Tejas also possess design advantages as Tejas has a smooth upper wing body blending possessed by other modern aircrafts like Rafale,Eurofighter Typhoon,F-22,PAK-FA and J-20 as well. This helps to avoid early detection as the corner reflections from AWACS aircrafts se searching from above resulting in lower RCS with missiles and external sores hidden under the wing. Tejas also has Y-intake also called bifurcated intake. Since,the engine fan blades are a prominient contributor in RCS, therefore Y intake buries the jet engine inside the fuselage so no engine parts are visible and thus increases the stealth characteristics. Tejas design incorporates a high wing body fuselage blending implemented from behind, resulting bouncing off of searching radar waves from behind.
Tejas canopy is also another feature as radar waves normally enter the cockpit reflects of objects & possibly return to the radar and even the HMD of pilot itself contributes to RCS, and to prevent this the canopy of Tejas is coated with a thin film transparent conductor of Indium Tin Oxide. The coating is thin enough that it has no adverse effect on pilot vision and can reflect the radar waves away from the radar antenna.
Another addition to its varied features is that 90% of surface of Tejas is constructed entirely of carbon composites which are less reflective than metals. The Tejas employs C-FC materials for up to 45% of its airframe by weight, including in the fuselage (doors and skins), wings (skin, spars and ribs), elevons, tailfin,rudder, air brakes and landing gear doors. Composite materials are used to make an aircraft both lighter and stronger at the same time compared to an all-metal design, and the LCA’s percentage employment of C-FCs is one of the highest among contemporary aircraft of its class. Use of composite materials helps to decrease RCS as against an all-metal airframe.
Tejas, being a single-engine fighter is inherently less suspectible to IRST and heat-seeking missiles and its low profile ( smallest 4th generation aircraft by dimensions ) makes it potent in high intensity dogfights. Though not designed as full-scale stealth it do possess some degree of stealth carrying on the legacy of inducing some degree of stealth in latest 21st century aircrafts.