Analysis:- Does LCA Tejas posses stealth?
Tejas is a 4+ generation, supersonic, highly maneuverable, multi-role, smallest and lightest in its class contemporary combat aircraft designed for the Indian Air Force designed and developed by DRDO. It is considered ‘game changer’ for India’s air defense preparedness.
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 is an aerodynamically unstable tailless compound delta-wing configuration, optimized primarily for maneuverability and agility. Designed to meet the tactical requirements of a modern air force, Tejas is a multi-role aircraft capable of comprehensive air superiority and air defense roles
The RCS of Tejas has been brought down significantly by modifying shape aspects within the limitations set by aerodynamics. Tejas got one of the best RCS value in the entire 4th generation fighters. Publically available figure is 0.5m2.
Tejas is a light aircraft. It is the smallest. It is difficult to have a view of it even in a WVR dogfight making it even more lethal and deadly.
The smooth upper wing body blending of Tejas gives it enough Stealth to avoid early detection. This kind of upper body blending is only being seen in later generation fighters from sukhoi, rafale, euro fighter typhoon, F-22, PAKFA, and J-20. This high wing body blending is the hall mark of even the fifth gen fighters, reducing the corner reflections from the awacs radars searching from above resulting in lower RCS with missiles and external sores hidden under the wing.
Tejas design incorporates a high wing body fuselage blending implemented from behind, resulting in smooth bouncing off of searching radar waves from behind whether they are x band or l band or aesa or mechanical it does not matter. If Tejas flies low hiding its stores no airborne radar will detect it from beyond 120 kms due to 0.3 sq meter rcs (From above, clarification needed).
Another stealth feature of Tejas is its Y intake also called bifurcated intake. Engine fan blades are one of the prominent sources of increasing radar cross section. This Y intake buried the jet engine inside the fuselage so no engine parts are visible and thus increases the stealth characteristics.
Tejas has Indium Tin Oxide coating on canopy. Radar waves normally enters the cockpit, gets reflected from objects & possibly returns to the radar. Even the HMD (Helmet-Mounted Display) of pilot itself contributes to RCS. 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.
Tejas has a smooth upper wing body blending i.e. having no clear dividing line between the wings and the main body of the craft (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 searching from above resulting in lower RCS.
Almost 90% of the surface of Tejas is made by carbon composites. These composites are much less reflective than metals. So this also makes Tejas,s RCS. Some reports saying India also developing carbon nano tube reinforced carbon composites for future use this will lead to further reduction in RCS
Due to its sheer small size, LCA-Tejas is very difficult to spot visually in close combat and use of specially developed Radiation-absorbent material coating and use of carbon composites will give it Smaller Radar cross sections (RCS) compared to larger aircraft .
Tejas has an Electronic Warfare suite. It includes a radar warning receiver (RWR), Missile Approach Warning (MAW) and a Laser warning receiver (LWR) system, Infrared & Ultraviolet Missile warning sensors, self-protection jammer, chaff, jaff and flares dispenser, an electronic countermeasures (ECM) suite and a towed radar decoy (TRD).
Tejas will incorporate AESA radar and already has BVR missiles like Derby (and Astra in future). Tejas has small RCS already and having these radar and armament, it will be able to detect enemy aircraft from far and launch attack and needs not to go close.
India’s indigenously developed Radiation-absorbent paint first applied on Soviet-era supplied Mig-21s had proven the reduction of its signatures considerably on Ground radars and LCA-Tejas no doubt will have smaller radar cross-section among non-stealth fighter jets but it doesn’t mean there are in the same category has 5th Generation Stealth fighters concluded Rajan.
Tejas is a single engine aircraft so it is inherently less susceptible to IRSTs compared to twin engine aircrafts. ADA pointed out that they already reduced the IR signature of Tejas. Making it more survivable against heat seeking missiles.