The Sinusoidal journey of LCA : TEJAS

Tejas Mk1

While the LCA program has endured waves of criticism, the fact is that it has helped grow a domestic aerospace eco-system in India that has the potential to be truly game changing. This was achieved starting from a situation in the late 1980s when India had lost most of its domestic capabilities for developing fighter aircraft on account of the HAL HF-24 Marut, India’s first homegrown fighter, not being succeeded by a follow on program. Owing to that, a lot of standard test facilities such as the LCA mini bird & iron Bird for flight control system Integration, a dynamic avionics integration rig, brake dynamometer & drop test rigs, secondary power system & fuel system test rigs, engine test bed, mobile electromagnetic interference/compatibility test facility etc. had to be set up in India from scratch by the Aeronautical Development Agency (ADA) which manages the overall LCA/Tejas development program.

The LCA is constructed of aluminium-lithium alloys, carbon-fibre composites (C-FC), and titanium alloy steels. 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, an indigenous quadruplex digital flight control system, indigenous mission computers and a modern glass cockpit capable enabling all weather day/night operations and the carriage of precision guided weapons, 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.

Today several domestic companies are involved in the Tejas program and some of them are now global Tier-II and III suppliers, having cut their teeth with this project which has seen the indigenous development and production of major sub-components such as aircraft-mounted accessories gearbox, carbon-carbon brake disc, heat exchangers, hydraulic & fuel valves etc. By value, 60 per cent of the components are now indigenous (although many are still built by HAL itself) and this is expected to climb to 75-80 per cent in the next few years.
Looking at developmental costs only, not on what had been spent towards producing delivery standard aircraft, all this has been accomplished with a total spend of about Rs 17,269 crores, spread over the Tejas Mk-I, MK-II and naval LCA programs. The total spend on the flagship Tejas MK-I program itself was around Rs 10,397 crores as of December 2015. And that the money for Tejas development was not sanctioned at one go. The full scale engineering development (FSED) phase-I for the Tejas program began only in 1993 with Rs 2188 crore being allocated to the program at the time which included Rs 560 crore sanctioned in 1983 for the project definition phase (PDP). The delay in FSED allocation was in no small measure due to the fact that India had to go through the tumult of the balance of payments crisis of 1990-1991.

The scope of the spend on phase-I was limited to building and flight testing two technology demonstrators only. One of which flew on 4th January 2001, overcoming American sanctions imposed post-Pokharan 2 in 1998 which saw the whole LCA National control law (CLAW) development team being thrown out of America. Undeterred by Lockheed Martin terminating its participation in the CLAW program, ADA scientists managed to develop flawless CLAW indigenously and the fact that the Tejas flight-test program has managed “over 2000 flights without any incidents” is a testimony to that effort.

That first flight gave enough confidence to the government to sanction Rs 3302 crores for Phase-II that involved the design, development and flight testing of 3 Prototypes and 8 Limited-Series. production (LSP) units. A final tranche of Rs 2476 crores was sanctioned as late as 2010, with the Mk-I heading towards Initial Operational Clearance-I (IOC-I) in 2011. This staggered financial approval scheme entailed major delays which also contributed
to increasing the need for several design upgrades towards obsolescence management.

The program materialized in the mid-1990s and the air staff requirement (ASR) of 1995 that was agreed to by ADA at the time broadly set the ultimate performance objectives for the project. With reference to the 1995 ASR, the Mk-I has already exceeded the angle of attack (AoA) requirement of 24 degrees, by some two degrees (i.e it has achieved 26 degrees), which is highly commendable and comparable to the best that the Mirage 2000 could do. This could even be increased to 28 degrees in the future. High alpha testing of course meant that parachutes and related systems developed by the Aerial Delivery Research and Development Establishment (ADRDE) for spin recovery were integrated into test aircraft as a safety measure, though they were of course never required to deploy. The Mk-I has also demonstrated +8G and has flown at a maximum Mach number of 1.6 at altitude.


The Tejas’ avionics – radar, laser and inertial navigation system – enhances the accuracy of IT’S weapons. The aircraft is fitted with a night vision compatible glass cockpit with Martin Baker (UK) zero-zero ejection seats.The cockpit has two 76mm×76mm colour liquid crystal multifunction displays developed by BEL and CSIO developed furnished by ELBIT DASH helmet mounted display and sight a liquid crystal return-to-home-base panel and keyboard. A helmet-mounted display and sight (HMDS) is also included, while the hands on throttle and stick control system minimises pilot workload and maximises situational awareness. Tejas has a quadruplex fly-by-wire digital automatic flight control and its navigation suite includes Sagem SIGMA 95N ring laser gyroscope inertial navigation system with an integrated global positioning system. The communications suite includes VHF to UHF radio communications with built-in counter-countermeasures, air-to-air and air-to-ground data link, as well as a HAL information friend-or-foe interrogator.

In addition, the cockpit includes an environmental control system developed by Spectrum Infotech of Bangalore. The avionics suite has an integrated utility health-monitoring system, ground proximity warning system, terrain referenced navigation system, instrument landing system, global positioning system, stores management system and three 1553B 32-bit mission computers. It also fited with an advanced electronic warfare suite with inbuilt jammer, was indeed a joint development programme between DRDO and Israel which has been confirmed by DRDO.

The suite is built around state-of-the-art Unified Electronic Warfare System (UEWS)—An internal EW system consisting of a Unified Receiver Exciter Processor (UREP) with advanced digital receiver/Digital Radio Frequency Memory (DRFM) concepts are integrated with Microwave Power Module (MPM)-based transmitter for LCA.
It is also equipped with Lock On Before Launch (LOBL) and look-down and shoot-down features. Computational and radar system of the aircraft have also received multiple upgrades to fire the advanced missile systems.
The aircraft’s electronic warfare suite, developed by the Advanced Systems Integration and Evaluation Organisation (ASIEO) of Bangalore, includes a radar warning receiver and jammer, laser warner, missile approach warner and chaff and flare dispenser.


Israel’s Aerospace Industries(IAI) Subsidiary Elta is developing an AESA version of it’s airborne fire control radar family designated EL/M 2052. This radar utilizes an array of transmit/receive solid-state modules designed to dynamically shape the radiation pattern using ultra-low side-lobe antenna. The radar supports pulse Doppler and two axis monopulse guard channel (Monopulse Antenna), providing all aspect, look-down shoot-down performance, operating simultaneous multimode Air to Air superiority and advanced strike missions.

The radar is based on Solid-State, Active Phase Array technology enabling the radar to achieve a longer detection range, high mission reliability and a multi target tracking capability of up to 64 targets. It can also support high resolution target identification and separation, performing raid assessment at long range, as well as surface moving target detection and ranging. In the anti-shipping role, the new radar provides long range target detection, classification and tracking(TWS). With high peak power, the radar supports simultaneous multimode operation. It can detect targets at very long range while tracking up to 64 targets, and simultaneously engaging several targets with missiles. In ground attack missions, the radar supports mapping, navigation and high resolution imagery(SAR), supported with Real Beam Map(RBM) and Doppler Beam Sharpening(DBS) modes. It is designed as a modular system, with built in growth capability, computation and memory reserves. It weighs about 140-170 kg and consume 4-10KVA, depending on the design configuration.

At Aero India 2009, it was revealed that the 3D MMR project has been superseded by the new 3D AESA FCR project led by LRDE. This Radar has the capability for Air to Ground Mapping and Targeting. This ‘HYBRID’ MMR has successfully undergone trials and will be supplied for the initial LCA Tejas fighters of which 2 squadrons have been ordered.
Electronics & Radar Development Establishment(LRDE) is developing an indigenously developed AESA Fire Controlled Radar called ‘UTTAM’. It’s being developed for the LCA Mk-II and presumably Mk-I will be upgraded with the system.

Hardware has already been realized for this radar which has a range of more than 100Km against small sized targets and rooftop testing is underway. Though it currently weighs 120Kg which is less than the EL/M 2052, will be no problem in integrating it with the LCA Mk-II & Mk-I. It is a 3D for fighters, a MMR follow on, the APAR project aims to field a full fledged operational AESA fire control radar for the MK-II.
BEL has also developed a RADAR WARNING RECEIVER (RWR) which is designed for fitment on fighter aircrafts and helicopters. It intercepts, detects and identifies all types of ground and air borne emitters (Pulse, CW, ICW, Pulse Doppler, Pulse agile, Frequency agile) and presents them on cockpit display unit with the help of alphanumeric/special colour symbols and audio tones.

Hindustan Aeronautics Ltd (HAL) chairman T Suvarna Raju recently stated that as Indian Air Force has cleared specification termed Standard of preparation 2018 (SOP-18) for improved LCA Tejas MK-1P which clearly mentions incorporation of few key requirements such as air-to-air refueling probe, podded self-protection jammer, integration of AESA radar and improved maintainability of the aircraft. First improved LCA Tejas MK-1P according to agreed schedules between HAL and IAF will have its first flight by 2017 and enter production by 2019 for which IAF already has committed 108 AESA equipped MK-1P type while earlier 40 ordered LCA Tejas MK-1 will come with Israel Aerospace Industries/ELTA Systems-supplied EL/M-2032 MMR fire control radar.

State-run Defence Research and Development Organization (DRDO) which has taken up the development of flight control radar for fighter aircraft with 100 km range and multi-mode operation. AESA radar development which has been started under Project “UTTAM” is still few years from entering production and was in development to be used in Tejas Mk-2 and possibly in Mk-I. DRDO currently has placed Airworthy radar processor and exciter receiver on a high rise platform in Mechanical Scanned Array (MSA) configuration for validation of various algorithms and wave-forms of the fire control radar.
The IAF has also had concerns about the Mk-I’s turn-around time and wanted certain modifications not all of which could be executed on the Mk-I design which has obviously been frozen ages ago. Over the years there were also additional requirements raised by the IAF to keep the aircraft contemporary which included things like the integration of a supersonic drop tank and these were met according to Dr Tamilmani. Anyway concerns about maintenance apart, the Mk-I has shown its reliability by flying up to three sorties on a single day during trials in both Leh and Jaisalmer on several occasions.
Moreover the Tejas Mk-I acquitted itself exceedingly well during Iron Fist 2013 with its deployed weapons being bang on target during that demonstration. Also during IF 2016, the Mk-I demonstrated air-to-air capability by firing a R-73E missile and air-to-ground capability by dropping laser guided bombs (LGBs) directed by a LITENING pod carried on one of its pylons. It demonstrated Astra BVRAAM and Derby Air to Air BVR missile successfully.
ENGINE : However, progress in the Kaveri development program was slowed by technical difficulties. In mid-2004, the Kaveri failed its high-altitude tests in Russia, ending the last hopes of introducing it with the first production Tejas aircraft. In 2008, it was announced that the Kaveri would not be ready in time for the Tejas. FYI only USA, Russia, Japan, Germany, France are the major engine producers in the world be it military or civilian. For a country like India which didn’t have a huge manufacturing and high-tech industry like these nations it was a tough job even China failed in producing engines. But the development of the Kaveri engine isn’t complete failure it is being reported that the kaveri engine would be used to Power UAV and UCAVs. As Kaveri engine failed to power Tejas, Production aircraft will be powered by the GE F404-GE-IN20 turbofan engine, rated at 85kN with afterburn.

On 19 February 2015 at the Aero India 2015, Director of DRDO Dr. Tamilmani told reports that a tender of joint venture on development of the engine is issued with General Electric, Pratt & Whitney, Rolls Royce, Snecma, Eurojet, NPO Saturn, Klimov and IHI to use current engine technology by combining Kaveri engine technology with JV engine to produce an engine capable of producing thrust of 110-125 kN. Full development of the K 9 and K 10 engine would be completed by 2019 to power the indigenous twin engine AMCA.

This article has been written by Kaustav Kar exclusively for
Qualification : B.Tech – Electronics and Communication
Location : Kolkata


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