HAL LCA Tejas:- India’s Lethal-Compact-Agile Aircraft

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.
The LCA has been designed and developed by a consortium of five aircraft research, design, production and product support organizations pooled by the Bangalore-based Aeronautical Development Agency (ADA), under Department of Defense Research and Development Organization (DRDO). Hindustan Aeronautics Limited (HAL) is the Principal Partner in the design and fabrication of the LCA and its integration leading to flight testing.

Stealth

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.

Canopy is another good radar reflector. Radar waves normally enter the cockpit reflects of objects & possibly return to the radar and even the HMD of pilot itself contributes to RCS. To avoid this Tejas canopy 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.
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

India already got patent in RAM coatings. The use of RAM coatings further decreases its RCS dramatically. Better coatings are under researching.

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.

Tejas incorporates a highly reliable quadruplex digital fly-by-wire Flight Control System. Digital fly-by-wire flight control system eases the handling by the pilot. The digital FBW system of the Tejas employs a powerful digital flight control computer (DFCC) comprising four computing channels, each with its own independent power supply and all housed in a single LRU

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Cockpit

The term Glass Cockpit refers to a modern cockpit in which all the round dialed electro-mechanical instruments have been replaced with Multi-Function Displays (MFDs) and a Head Up Display (HUD). A glass cockpit uses several displays driven by flight management systems, which can be adjusted to display flight information as needed. This simplifies aircraft operation and navigation and allows pilots to focus only on the most pertinent information. An advanced cockpit enhances the comfort level of pilots.

The new generation glass cockpit of Tejas comprises Multi Function Displays (MFD), Head Up Display (HUD) and Stand by Instrumentation System driven by Open Architecture Mission and Display Computer. This provides effective Human Machine Interface (HMI). The advanced utility and health management system provides system health and warnings to the pilot through an Open Architecture Computer (OAC).

Radar

Tejas will feature AESA radar. Currently Tejas uses EL/M 2032 radar in MK 1 version. Tejas MK 1A will use EL/M 2052 AESA radar and indigenous UTTAM AESA radar is under development. Due to the small nose cone, AESA in Tejas obviously have a lower range, but it will be well integrated with in the IAF network, and give a quantum technology jump to IAFs combat ability.

Uttam AESA is indigenously developed active electronically scanned array (AESA) fire control radar. It is being developed for the LCA Mk2 and Mk1 (presumably Mk1s will be upgraded with the system) and also other aircraft upgrades such as the IAF’s Jaguars and MiG-29Ks. Hardware has already been realized for this radar which has a range of 100 km against small fighter sized targets and rooftop testing is underway. Though the Uttam AESA currently weighs 120 kg which is some 40 kg more than the current MMR, there will be no problem in integrating it with the LCA Mk-II which can easily carry radar of this weight.

Fly By Wire system

An unstable design like Tejas needs powerful flight controls to maintain artificial stability in normal flight conditions. For that, Tejas has the world’s most advanced Quadruplux Digital Fly by Wire system. This is another very complex technology. Mirage2000 on the other hand has a basic analog Fly by Wire system.
Weapons

Any modern fighter is only as good as the weapons she can deliver on target. The Tejas is designed to carry a veritable plethora of air to air, air to surface, precision guided and standoff weaponry. In the air to air arena, the Tejas carries long range beyond visual range weapons, with highly agile high off-boresight missiles to tackle any close combat threat. A wide variety of air to ground munitions and an extremely accurate navigation and attack system allow it to prosecute surface targets over land or at sea with unparalleled accuracy, giving the Tejas true multi/swing role capability.

Elta litening pod

Litening is a sensor pod which caters to the need of day & night precision strike capability. Low level night flights, laser spot detection and tracking, co-operative target illumination, optical BVR target identification and infrared / secondary navigation. Almost all 4th gen fighters relay on externally mounted pods for some functions. It has a flexible flight envelop includes vertical 9g maneuvers and speed up to mach1.2 at low level and mach 1.8 at 13000 ft.

Astra Missile

Astra is an active radar homing beyond-visual-range air-to-air missile (BVRAAM) developed by the De fence Research and Development Organization, India. Astra is designed to be capable of engaging targets at varying range and altitudes allowing for engagement of both short-range targets (up to 20 km) and long-range targets (up to 80 km) using alternative propulsion modes. The Astra is a Beyond Visual Range (BVR) missile capable of being launched from India’s Sukhoi-30 MKI twin-jet air superiority fighter. The Indian Air Force currently operates roughly 200 total Su-30 MKI, but plans to eventually operate around 270. The Astra is 149 inches in length, making it the most compact missile developed indigenously in India capable of supersonic speeds.

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The highly agile, accurate and reliable missile features high single-shot kill probability (SSKP) and is capable of operating under all weather conditions.Length of the weapon system is 3.8m, while its diameter is 178mm, and an overall launch weight is160kg. Its low all-up weight provides high launch range capability and the system’s airborne launcher can be used with different fighter aircraft.

The Astra BVR air-to-air missile is powered by a smokeless, single stage, solid fuel propulsion system. It can intercept and destroy enemy targets with a launch speed between Mach 0.4 and Mach 2.Launch range and launch altitudes of the weapon system are 80km and 20km respectively. The missile can achieve 40 g turns near sea level while engaging a moving target

Derby BVRAAM missile

The Derby BVRAAM missile, which enables the aircraft strike aerial targets, has a defined operational range of over 50 kilometres. The missile which is capable of attaining speeds up to Mach 4 is guided by advanced and sleek active radar. Derby has been in operation with the Indian Air Force (IAF) and the Indian Navy for well over a decade.

RAFAEL’s Derby fire-and-forget missile will serve as the Tejas’ initial medium range air-air armament. TheBrahmos NG supersonic cruise missile is being developed for the Tejas.The long range Nirbhay cruise missile is being considered for use on the Tejas, but will require extensive modifications, including being shortened by 25%, to fit the aircraft.

Usefulness for IAF :

Now that its effectiveness in Air Defence is established we can now gauge its usefulness.

Induction of 120 Tejas will result in SU 30 MKIs focusing on offensive operations as Tejas along with MIG 29s in combination with AWACS and SAM sytems will take up Air defence duties . This will give Air force roughly around 500 Aircraft for offence .
Also beeing deployed in forward airbases Tejas will be a key component of cold start doctrine. Providing air support, reconnaissance , patrol and air defence for mechanised combat groups in rapid mobilisation required for cold start .

Beeing Multirole,cheap to build and operate , LCA Tejas and its variants are key to IAF operating economically in peace and war time . Enabling IAF to keep operating at a high tempo , keep pilots better trained and operationally superior. Resulting in a sustainable peace time & wartime advantage.
Finally Tejas is an indigenous fighter aircraft. We can make as many as we need, when we need . The source code of the flight & weapon control system software is proprietary and open to integration with all weapons . We can modify the fighter, change configuration and deploy at will.

Conclusion

Tejas is a 4+ generation fighter which can give tough competition to any of the fourth gen fighters. Only Gripen NG has a considerable advantage over Tejas due to its superior avionics. After Tejas mk2 comes in Gripen won’t also be invincible.

 

 

 

Source : RCA of Tejas(Quora), Usefulness for IAF ( Quora ), Astra Missile(Source)

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