Monday, March 4, 2024

Viewpoint : New Indian HAL Tejas light multirole fighter

The HAL LCA or lovingly named by Shri Atal Bihari Vaypayee as the Tejas meaning radiant has always been in the forefront of controversies but apart from that one of the most advanced delta winged aircraft designed and built by nation known for being the world’s largest weapons importer.

So what makes this aircraft so special ?

Why did the Chinese known for their master skills in the field of reverse engineering and building equipment stated that the Tejas is an aircraft of the future.

HAL HF-24 Marut
HAL HF-24 Marut


  In the year 1969 the government of India on the advise of Hindustan aeronautics limited accepted it’s proposal to design a fighter based on the Air staff requirement on a proven engine.  HAL completed the study for the fighter in the year 1975 but the project failed due to various international political and economic reasons as an ideal foreign engine cannot be procured.
 In the year 1983 when IAF realized the need for a new combat aircraft for two main reasons. The first reason was to replace the Mig-21s inducted in the beginning of the year 1965 which formed the backbone of the IAF was soon approaching the end of their service life
 The “Long Term Re-Equipment Plan 1981” noted that the MiG-21s would be approaching the end of their service lives by the mid-1990s, and that by 1995, the IAF would lack 40% of the aircraft needed to fill its projected force structure requirements. The LCA programme’s other main objective was an across-the-board advancement of India’s domestic aerospace industry. The value of the aerospace “self-reliance” initiative is not simply the aircraft’s production, but also the building of a local industry capable of creating state-of-the-art products with commercial spin-offs for a global market.

 In the year 1984 the Indian government proceeded with the decision to establish ADA ( Aeronautical development agency) to manage the LCA program While the Tejas is often described as a product of Hindustan Aeronautics Limited (HAL), responsibility for its development belongs to ADA, a national consortium of over 100 defence laboratories, industrial organisations, and academic institutions with HAL being the principal contractor. Through the LCA program the Government decided to master the 3 most sophisticated skills any aircraft manufacturing nation should the Fly-by wire system (FBW), the flight control system (FCS), multi mode pulse doppler radar and the afterburning turbofan engine.

  The IAF’s Air Staff Requirement for the LCA were not finalised until October 1985. This delay rendered moot the original schedule which called for first flight in April 1990 and service entry in 1995; however, it also gave the ADA time to better marshal national R&D and industrial resources, recruit personnel, create infrastructure, and to gain a clearer perspective of which advanced technologies could be developed locally and which would need to be imported. Out of a total of 35 major avionics components and line-replaceable units (LRUs), only three involve foreign systems. These are the multi-function displays (MFDs) by Sextant (France) and Elbit (Israel), The helmet-mounted display and sight (HMDS) cueing system by Elbit, and the laser pod supplied by Rafael (Israel).. Production aircraft are expected to have MFDs from Indian suppliers. A few important items of equipment (such as the Martin-Baker ejection seat) have been imported.



 In the year 1990 the final design for the Tejas was frozen it was going to be a small tailless delta winged machine with relaxed static stability (RSS) and control-configuration for enhanced maneuverability. Soon after the design finalization a review committee was formed in the month of May 1989 to report the thing necessary like  infrastructure, facilities and technologies in India had advanced sufficiently in most areas and that the project could be undertaken. Project definition commenced with France’s Dassault Aviation in a reviewing/advisory role; this phase, costing 560 crore (US$85 million), was completed in September 1988. the route of a two-stage full-scale engineering development (FSED) process was opted for.

The first Phase of the project was known as Phase – 1 which focused mainly on the  feasibility of the project and the Design and development of two technology demonstrator vehicle known as TD-1 and TD-2 and two prototype vehicles known as PV-1 and PV-2.   The first phase was completed on March 2004 when the TD-1 finally flew on 4th Jan 2004 The second phase of the project called Phase – 2 commenced in the year 2001 in the month of November consisted of the manufacturing of three more prototype vehicles (PV-3, PV-4 and PV-5), leading to the development of the final variant that would join the air force and the navy and 8 Limited Series Production (LSP) aircraft, and establishment of infrastructure for producing 8 aircraft per year.[25] The phase cost ₹3,301.78 crore, and an additional amount of ₹2,475.78 crore was given for induction into Indian Air Force by obtaining IOC and FOC. The total cost for development of Tejas (including PDP, Phase 1 and Phase 2) was ₹7,965.56 crore as of August 2013.

                                                      DESIGN OVERVIEW

The Tejas is a single-engine multirole fighter much like the Mirage-2000,F-16,Saab Gripen and FC-1 xialong of Chian except one difference which is that it features a tailless, compound delta planform ( a planform is the shape and layout of a fixed-wing aircraft’s wing.)and is designed with “relaxed static stability” for enhanced  maneuverability. Originally intended to serve as an air superiority aircraft with a secondary ground-attack role, its flexibility permits a variety of guided air-to-surface and anti-shipping weapons to be integrated for multirole and multimission capabilities. The tailless, compound-delta planform is designed to be small and lightweight. 

Air India 2007 (c)
Air India 2007 (c)

The Tejas is made up of light composites which helps in making the aircraft lighter For example
a recent comparison showed that the Tejas being lighter than the Fc-1 xialong helped the Tejas to carry more fuel and weapons than the FC-1. Along with the weight reduction it also requires fewer use of rivets and joints reducing the crack and fatigue on the body of the aircraft and durability. 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, 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. Though some say it’s an expensive method while some say it helps in reducing costs but one this for sure it reduces the production timing of per aircraft it takes 7 months to produce a composite based aircraft while 11 months to produce an all metal Tejas as said “A stitch in time saves nine”.


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 Bharat Electronics 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.

An advanced cockpit enhances the comfort level of test pilots.

Weapons and countermeasures

The aircraft has eight external hardpoints to carry stores, with three under each wing, one on the centre fuselage and one installed under the air intake on the port side.

A 23mm twin-barrelled GSh-23 gun with a burst firing rate of 50 rounds a second and muzzle velocity of 715m a second is installed in a blister fairing under the starboard air intake.The aircraft can be armed with air-to-air, air-to-ground and anti-ship missiles, precision-guided munitions, rockets and bombs. Electronic warfare, targeting, surveillance, reconnaissance or training pods can be carried on the hardpoints. Drop tanks can also be carried.

In October 2007, the aircraft successfully test-fired the R-73 air-to-air missile.The Vympel R-73 (Nato codename AA-11 Archer) missile is an all-aspect short-range missile with cooled infrared homing. It can intercept targets at altitudes between 0.02km and 20km, g-load to 12g and with target speeds of up to 2,500km/h.

The Indian Government will purchase Derby beyond-visual-range air-to-air missiles (BVR-AAM) from Rafael Advanced Defence Systems to incorporate on 200 aircraft..These missiles are expected to be delivered by the end of 2012. They will supersede Astra BVR-AAM and accelerate the development process. The weapon tests on Tejas were carried out at the Pokhran range in September 2011.

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.

Sensors and radar

Electronics Research and Development Establishment and HAL have jointly developed the aircraft’s multimode radar. The radar has multiple target search and track-while-scan and ground-mapping modes of operation. It includes pulse Doppler radar with Doppler beam shaping, moving target indication and look-up / look-down capability. The radar is mounted in a Kevlar radome which now has a range of 40 km to 50 Km but after the upgradation it would be placed in a quartz radome which would increase the range to 80 KM. MMR is to perform multi-target search, track while scan(TWS), and ground-mapping functions. It features look-up/look-down/shoot-downmodes, low/medium/high pulse repetition frequencies (PRF), platform motion compensation, doppler beam-sharpening, moving target indication(MTI), Doppler filtering, constant false alarm rate (CFAR) detection, range-Doppler ambiguity resolution, scan conversion, and online diagnostics to identify faulty processor modules. Due to long delays in the project it was decided that a hybrid ELTA EL/M-2032 radar would be placed instead of the pulse doppler radar.

Turbofan engines and performance
he prototype development aircraft are fitted with General Electric F404-GE-F2J3 turbofan engines with afterburn.Production versions will be fitted with one General Electric 85kN F404-GE-IN20 turbofan engine with full authority digital engine control. HAL placed an order for 24 F404-GE-IN20 engines in February 2007.


Planned production variant

So far there has been reports of two planned variants of the Tejas one is LEAD-IN-FIGHTER-TRAINER and the other is the Naval version which would operate from the the future Indian aircraft carriers. The Naval version carried out it’s first flight from a shore based test facility on February 7th, 2015. The Naval variant has a dropped down nose and a strengthened undercarriage which facilitates the ability to land on aircraft carriers under harsh conditions.

” The single-seater Light Combat Aircraft (LCA) Navy prototype for the Indian Navy, NP-2, has successfully completed its first flight, and has since flown a further three times.
The aircraft conducted its maiden flight on 7 February at the Hindustan Aeronautics Ltd (HAL) airfield in Bangalore. According to HAL, the aircraft performed “flawlessly” during the 35-minute test flight.NP-2 embodies several improvements based on feedback from flights of the first flight test article, the two-seater NP-1. After a handful of flights between April and July 2012, the NP-1 flight test programme saw the aircraft go through several modifications including structural revisions to enable the landing gear to handle the high aircraft sink rates associated with carrier landing operations. Other work included improvements to the aircraft’s environmental control system (ECS) and fuel system. Airbus Defence & Space (formerly EADS) has been providing technical assistance with these activities.

The NP-2’s avionics suite incorporates “all requisite” hardware, according to project officials. The airframe also has been modified to incrementally accept additional avionics and control system updates such as the Leading Edge Vortex Controller (Levcon) Air Data Computer, an auto throttle, and external and internal angle of attack lights, using a ‘plug-and-play’ systems approach, said HAL.The NP-2 is to be the lead aircraft for arrestor hook integration, the Rafael Derby Beyond Visual Range air-to-air missile (BVRAAM), and tactical datalink, said HAL in a statement.

The naval LCA project was approved by the Indian government in 2003, with the first stage of development comprising two LCA Navy Mk 1 flight test articles – a trainer prototype (NP-1) and a fighter aircraft prototype (NP-2) – and a static test article, all built to the Mk 1 design. Since then, another trainer, NP-5, has been approved; its airframe is under construction.In addition, two more Mk 1 fighter aircraft prototypes are planned to be built – although the Indian Ministry of Defence (MoD) is yet to formally fund these test articles.

The second stage of the LCA project involves building two Mk 2 flight test articles – NP-3 and NP-4, both in a single-seater configuration. The concept design of the definitive Mk 2 version is understood to have been completed. The Mk 2 is, in essence, a major redesign of the Mk 1 for enhanced mission performance and improved maintainability.The Mk 2 will incorporate a more powerful General Electric F-414 INS6 engine as well as landing gear, arrestor hook, and internal layout developments, a reduced nose droop to improve aerodynamic performance, and other drag reduction features.

It will also feature a fuel dump system, increased fuel capacity, a retractable inflight refueling probe, and an onboard oxygen generation system.The avionics suite will feature the new Uttam active electronically scanned array (AESA) multimode radar, an upgraded flight control computer, and an improved cockpit layout. Defensive systems will be enhanced with a new integrated electronic warfare suite.

Crucially, unlike the LCA Navy Mk 1, which was adapted from an air force variant, the LCA Navy Mk 2 will be optimised ‘ab initio’ to be a carrier-borne naval fighter aircraft, according to a project official. It is understood that the Mk 2’s first flight is now expected to take place around 2020.According to industry sources, the Indian Navy has a requirement for over 50 Mk 2 airframes, to be formed into two squadrons.” as stated in recent article in this article on IHS Jane.

The more advanced and awaited version of the Tejas is called the Tejas MK.2 Light Combat Aircraft (LCA) Tejas Mk-II would be an improved version of LCA Mk-I. Some of the new systems / technologies, like Active Electrically Scanned Array (AESA) Radar, Unified Electronic Warfare (EW) Suite, On Board Oxygen Generation System (OBOGS), Upgraded Avionics, etc. are to be included in LCA Tejas Mk-II to make the aircraft more contemporary. Technologies, systems engineering and experience gained during development of LCA Tejas Mk-II would benefit the development of Fifth Generation Aircraft indigenously. According to various reports the mark.2 won’t be flying before 2020.

Delays by India’s state-owned Hindustan Aeronautics Limited (HAL) in developing the upgraded Tejas Light Combat Aircraft (LCA) Mk 2 are likely to pose operational problems for the Indian Air Force (IAF), which is facing a steady decline in its fighter squadrons. According to official sources HAL recently proposed to the IAF that, instead of waiting for it to design the more capable LCA Mk 2, the air force should acquire the under-development Tejas Mk 1A variant, which is marginally more proficient than the existing Mk 1.

MK-I + is in-house project initiated by HAL after IAF agreed to looking into the project owing due to delays in whole Tejas program .HAL has asked Indian air force to order as much as 80 aircrafts over 40 already ordered for Tejas MK-1 aircrafts. IAF had requirement of 83 MK-II aircrafts which HAL feels can be substituted by MK-I + with marginal drop in performance. IAF’s LCA aircraft type requirements will be close to 300 aircrafts according to many Defence analyst in a decade, since by 2019 all Light weight Mig-21 aircrafts will be phased out.

So why is the Tejas program delayed by so many years ?

I always hear people comment that due to lack of funding,bureaucracy,political reasons it was delayed but that is only a small portion of the story

Development of a FBW flight control system requires extensive knowledge of flight control laws and the expensive writing of a considerable amount of software code for the flight control computers, as well as its integration with the avionics and other electronic systems. When the LCA programme was launched, FBW was a state-of-the-art technology and such a sensitive one that India could find no nation willing to export it. Therefore, in 1992 the LCA National Control Law (CLAW) team was set up by the National Aeronautics Laboratory to develop India’s own version. The CLAW team’s scientists and mathematicians were successful in developing their control laws, but could not test them since India did not possess advanced real-time ground simulators at that time. Accordingly, British Aerospace (BAe) and Lockheed Martin were brought in to help in 1993, but the effort required for the Aeronautical Development Establishment to code the control laws into the FCS software proved a much larger job than originally anticipated
As a consequence of the embargo imposed on India after its nuclear weapons tests in May 1998, many items originally planned to be imported were instead developed locally; these sanctions contributed to the prolonged delays suffered by the LCA. Along with the sanctions the 1991 economic crisis left India with money to pour into R&D. So after the sanctions were imposed it took us a lot of time to develop those systems which were to be imported. Basically we started from scratch.

KAVERI ENGINE WAS DECIDED TO EQUIP HAL TEJAS.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


An evaluation of the Tejas’ combat capability must consider its flying performance, its avionics and the weapon load it carries. At IOC, it already flies at Mach 1.6 (2,000 kmph); operates up to 15,000 metres (50,000 feet); and carries 3,500 kg of mission payload, including weapons and sensors. Its combat radius is 300-350 km, which would be extended next year through in-flight refuelling. By FOC next year, this performance would be enhanced.

The Tejas has been designed as a multi-role fighter. It can engage enemy aircraft with the R-73 short-range air-to-air missile (SRAAM); by FOC next year, more potent air-to-air missiles, probably the Israeli Derby and Python, would be integrated. Against ground targets, the Tejas carries conventional and laser-guided bombs. Next year, it will have an integral 23 millimetre Gasha cannon.

The Tejas’ avionics – radar, laser and inertial navigation system – enhances the accuracy of these weapons. Its highly rated Elta EL/M-2032 multi-mode radar provides multi-role capability, allowing the pilot to fire air-to-air missiles at enemy aircraft; and also bomb ground targets with a highly accurate navigation-attack system. The pilot operates his weapons through a head-up display (HUD), or through a helmet-mounted sighting system (HMSS) by merely looking at a target. Experienced fighter pilots say the Tejas is the IAF’s most “pilot friendly” fighter.

Although it is one of the world’s lightest fighters, the Tejas’ weapons load of 3,500 kg compares well with most IAF fighters, including the Mirage-2000, Jaguar, upgraded MiG-27 and the MiG-21. Depending on the mission – strike, photoreconnaissance, or air defence – its eight hard points can carry missiles, bombs, fuel drop tanks or a targeting pod. It can bomb targets and fire missiles as accurately as the Sukhoi-30MKI. The latter scores mainly in its longer range and bigger weapons load, both stemming from its much larger size.

The Tejas’ capability is best known to the air force and navy test pilots in the National Flight Test Centre, who have tested it in 2,400 flights. They claim it may be more versatile than the MiG-29 (primarily built for air-to-air combat); the MiG-27 and the Jaguar (both oriented to ground strike); and all variants of the MiG-21, including the multi-role BISON.

The Tejas’ likely adversary, the Pakistan Air Force’s F-16 fighter, has a slightly larger flight envelope, but the Tejas’ superior avionics give it a combat edge over the PAF’s older F-16A/Bs (currently being upgraded in Turkey); and superior to their new JF-17 Thunder light fighter, co-developed with China. Only the PAF’s 18 new F-16C/D Block 52 fighters, flying since 2010-11 from Jacobabad, may be a match for the Tejas.

Said an NFTC test pilot during the IOC ceremony on December 20: “As a multi-role fighter, the Tejas is at least the equal of the IAF’s upgraded Mirage-2000. It can more than hold its own in our operational scenario.”

Battlefield employment
The IAF’s operational plans earlier had strike aircraft like Jaguars or MiG-27s attacking ground targets, while air defence fighters like the MiG-29 covered them from enemy aircraft. Now mission-specific aircraft are giving way to multi-role fighters, which can do both jobs. This doctrinal shift stemmed from the Mirage-2000, the IAF’s first multi-role fighter, which was inducted in the mid-1980s. The Mirage-2000 inspired the Tejas in both role and design.

Today, the IAF controls the aerial battle from airborne early warning and command (AEW&C) aircraft like the Phalcon, a giant radar mounted on a transport aircraft. Flying over the battle space and scanning 400 kilometres on all sides, the AEW&C identifies enemy aircraft and, over a secure datalink, allocates fighters from nearby bases to tackle the intruders. The AEW&C also orders up fighters to strike ground targets in the land battle.

“Tejas light fighters, located at forward airbases like Pathankot, Ambala, Sirsa or Jodhpur are ideal for missions in the vicinity of the border. They are close at hand and react quickly. Being far cheaper, they can be bought and used in larger numbers, saturating the enemy’s radar picture and complicating his decision-making,” says a senior former IAF planner.

“With an AEW&C guiding the Tejas directly to the target, it does not need a long operating range; and its combination of Elta-2032 radar and air-to-air missiles, are lethal against most contemporary fighters.”

Employing the Tejas for the tactical battle would allow the IAF’s heavy, multi-role fighters like the Su-30MKI and Rafale to be focused on targets deep inside enemy territory, which are beyond the range of the Tejas – such as major air bases, military headquarters and strategic infrastructure. These fighters, which carry far more fuel and weapons, can take off from bases deep inside India, bomb targets deep inside enemy territory, and also shoot down enemy fighters.

Yet, heavy fighters have their downsides. Maintenance is complex, with half the Su-30MKI fleet usually unavailable for operations. Enemy radar picks up the heavy fighters more easily; the Tejas is smaller, and also stealthier, being largely fabricated from composite materials. Moreover, the loss of a Sukhoi-30 is a Rs 400 crore blow; a Tejas will probably costs one-third of that.

Many IAF planners advocate a balanced air force, with a mix of light and heavy fighters. Light fighters like the Tejas would respond to the tactical battle, while heavier fighters, with their longer range and greater strike power, could tackle more strategic targets.

The light fighter has a long tradition in the IAF. On December 17, Defence Minister A K Antony told parliament that 254 MiG-21s – or 12 squadrons worth -still remain in service. The Tejas provides an effective replacement for those obsolescent machines. HAL’s new assembly line in HAL Bangalore plans to build 8 Tejas Mark I fighters annually, stepping up capacity to 16 fighters per year. If the IAF absorbs HAL’s entire production capacity, it would have 3-4 squadrons of Mark I fighters; after which the Mark II would start rolling off the line. Creating 12 Tejas squadrons to replace the MiG-21 would retain a balanced air force, and also galvanise the aerospace production eco-system needed for developing the IAF’s future fighters.

Tejas’ record-breaking performance
On December 27, the Tejas flew its 500th test-flight this year, a record-breaking performance. Flying from seven IAF bases spread around the country, the testing included shutting off and restarting the Tejas’ engine mid-flight, firing missiles, dropping bombs and validating emergency procedures. The flight-test programme will continue until the Tejas gets its Final Operational Clearance (FOC), which is targeted for end-2014.


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Executive Editor

About author:

Colton Jones
Colton Jones
Colton Jones is the deputy editor of Defence Blog. He is a US-based journalist, writer and publisher who specializes in the defense industry in North America and Europe. He has written about emerging technology in military magazines and elsewhere. He is a former Air Force airmen and served at the Ramstein Air Base in Germany.



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