Tejas

The HAL Tejas (lit. 'Radiant') is an Indian single-engine, 4.5 generation, delta wing, multirole combat aircraft designed by the Aeronautical Development Agency and manufactured by Hindustan Aeronautics Limited (HAL) for the Indian Air Force (IAF) and the Indian Navy. The aircraft made its first flight in 2001 and entered into service with the IAF in 2015. It is the smallest and lightest of the supersonic fighter jets of its generation. The aircraft was officially named as Tejas in 2003. The name means 'radiance' or 'brilliance' in Sanskrit, and continued an Indian tradition of choosing Sanskrit-language names for both domestically produced and imported combat aircraft. Tejas is the second jet powered combat aircraft developed by HAL, after the HF-24 Marut. It has two production combat variants – Mark 1 and Mark 1A apart from trainers. In 2016, the Mark 1 aircraft had an indigenous content of 59.7% by value and 75.5% by the number of line replaceable units, which was increased in the 1A variant. As of November 2025, the IAF has about 30 Mark 1 aircraft and six trainers in its inventory across two squadrons. The first squadron, No. 45 Squadron IAF (Flying Daggers) became operational in 2016 and is based at Sulur in the southern state of Tamil Nadu. The second squadron, No. 18 Squadron IAF (Flying Bullets) is based at Naliya in Gujarat in Western India. The IAF has 141 combat aircraft of the Mark 1A type on order, in addition to 41 trainers. The IAF plans to procure at least 324 aircraft or 18 squadrons of Tejas in all variants, including the heavier Tejas Mark 2 which is currently being developed.

Development

LCA programme

In the 1980s, the Indian Air Force (IAF) had been operating ageing fighter aircraft such as the MiG-21. The MiG-21 had been the mainstay of the IAF since 1963, and the IAF had operated 874 of these aircraft in the past. The Long Term Re-Equipment Plan of 1981 of the Ministry of Defence noted that most of these fighter aircraft were approaching the end of their service lives by the early-1990s, and that by 1995, the IAF would be 40 percent short of the aircraft needed to fill its projected force structure requirements. In 1983, the Government of India established the Light Combat Aircraft (LCA) programme with the initial goal of developing a new light combat aircraft to replace the ageing fleet of the IAF. In 1984, the government established the Aeronautical Development Agency (ADA) under the aegis of the Defence Research and Development Organisation (DRDO) to manage the LCA programme. The ADA was entrusted with the design and development of LCA while Hindustan Aeronautics Limited (HAL) was chosen as the principal contractor. The government's requirements for the aircraft included the following: fly-by-wire flight control system, multi-mode pulse-doppler radar, and afterburning turbofan engine. The project definition phase commenced in October 1986. French company Dassault-Breguet acted as a consultant for the design and system integration of the planned aircraft. Kota Harinarayana was appointed as the director and chief designer of the LCA programme. While the project was initially conceived to replace the MiG-21 aircraft, the Minister of Defence told the Indian Parliament in 2021 that the aircraft is no longer considered as a replacement for the MiG-21, and is part of a general IAF fleet modernisation programme.

=== Design === The design of the LCA was finalised in 1990 as a small tailless compound delta wing design with relaxed static stability. To provide enhanced manoeuvrability, it was planned to be a control configured vehicle incorporating a digital fly by wire flight control system. Dassault-Breguet offered a hybrid fly by wire flight control system for the project, consisting of three digital channels and one analog channel, with a redundant analog channel as a back up. However, the ADA favored a quadruplex (four) digital channel flight control system. In 1992, a dedicated National Control Law team (CLAW) was set up by the National Aerospace Laboratories (NAL) to develop an indigenous fly by wire flight control system for the aircraft. While initially Lockheed Martin was proposed as a partner, it did not materialise following a United States led embargo in response to India's second nuclear tests in 1998. This delayed the programme partly by about 18 months.

The quadruplex digital fly-by-wire flight control system was developed in house for the LCA. The CLAW team completed the design and integration of the flight control laws with the flight control system software, with the aid of an Iron Bird test rig. The flight control system conducted over 50 hours of pilot testing on the test rig. Aerodynamic characterization research was conducted at NAL's 1.2 m (3 ft 11 in) tri-sonic wind tunnel facility. For the multi-mode radar (MMR), the team intended to use the Ericsson–Ferranti PS-05/A I/J-band multi-function radar used on Saab JAS 39 Gripen. However, DRDO later decided to develop an indigenous radar for the aircraft. DRDO's Electronics and Radar Development Establishment (LRDE) laboratory and HAL were jointly assigned the MMR development programme, and with the work commencing in 1997. The Centre for Airborne Systems was responsible for the MMR's test programme, and a HS-748 airborne surveillance aircraft was re-fitted for the purpose. By 2005, only two radar modes–the air-to-air look-up and look-down were successfully tested, and the performance of other modes that had been tested were rated as sub-optimal. The problem was attributed to the lack of compatibility between the radar and the LRDE's signal processor module. The development of MMR was later abandoned in favour of using a foreign developed radar as an interim option. The Israeli Elta EL/M-2032 multi-mode and EL/M-2052 Active electronically scanned array radar units were selected for the Mk1 and initial Mk 1A aircraft respectively. In 2012, the DRDO started development of the Uttam AESA Radar, which was undergoing trails as of 2024. The ADA was successful in the development and manufacturing of carbon fibre composite structures and skins, and a glass cockpit for the aircraft. The Autolay computer-aided design software developed as part of the LCA programme was later licensed to Airbus for its A380 wide-body aircraft project. The government's self-reliance goal oriented development considerably increased the sourcing of indigenous components for the programme and contributed to the expansion of the aviation industry. For the LCA programme, Amphenol provided loom assemblies, Lakshmi Machine Works produced air intakes, and Tata Advanced Systems manufactured the composite parts.

Prototypes and testing

On 4 January 2001, the first technology demonstrator (TD-1) successfully achieved flight. The second such aircraft (TD-2) began testing in 2003. The first production variant (PV-1) made its maiden flight in 2003. The first trainer variant (PV-5) was rolled out in 2009 and made its first flight on 26 November 2009. A total of two trainer prototypes were built and designated PV-5 and PV-06. The first naval prototype, designated NP-1, made its first flight on 27 April 2012. It was a twin-seater aircraft, while the second naval prototype, designated as NP-2, was a single seater. Both naval prototypes were used extensively for various aircraft carrier-related trials at the Shore Based Test Facility in Goa. NP-2 was used in the actual carrier trials, where it made an arrested recovery and ski-jump assisted take-off from the aircraft carrier INS Vikramaditya in January 2020.

The first Limited Series Production aircraft (LSP-1) performed its maiden flight on 25 April 2007. A total of seven limited series production (LSP) aircraft were built. The LSPs were extensively used for developmental trials such as weapon testing – involving test firing of the R-73 and Python-5 close combat missiles, the I-Derby ER beyond visual range air-to-air missile and guided–unguided munition releases. The LSPs were also used for sensor trials involving integration and testing of the Israeli Elta EL/M-2032 multi-mode radar, and EL/M-2052 AESA radar, and the Indian Uttam AESA Radar and Rafael Litening targeting pod. The Uttam radar was integrated on the Tejas LSP-2 and LSP-3, and logged about 30 hours of flight testing on the Tejas alone. The high altitude trials and hot weather trials were carried out with the LSPs and the PV-3 prototype, in IOC and FOC configurations. These trials were mainly focused on assessing the performance of the various sensors and avionics on board, at temperatures ranging from below -10 degree Celsius to more than +45 degrees Celsius.

Sea trials to assess the radar performance in air-to-air and air-to-sea modes at various altitudes were carried out in 2010. Flutter vibration tests were also carried out in different configurations at high angle of attack (AoA) to assess the structural integrity across the flight envelope. LSP-4 completed the successful trial of BDL developed Counter Measure Dispensing System (CMDS) with R-73 missile on 2 December 2010. It worked well Open Architecture Mission Computer and Digital Stores Management System. In the second half of 2012, the Tejas fleet was grounded for over three months and the ejection system had to be modified to resume flight tests by the end of 2012. In 2013, Tejas (LSP-7) conducted an inflight engine relight test at high altitude to assess the engine response on flameout, a critical parameter for operational clearance. The inflight engine relight test is crucial for single engine combat aircraft. On 15 April 2023, HAL received a flight clearance certificate for the Aircraft Mounted Accessory Gear Box (AMAGB) bearings and power take-off shaft. The Centre for Military Airworthiness and Certification (CEMILAC) also gave clearance for the pre-production of landing gear seals developed by the Combat Vehicles Research and Development Establishment (CVRDE) and Fluoro Carbon Seals Limited.

Operational clearance

In December 2006, the IAF announced that it would form an "LCA Induction Team" to manage the aircraft's service introduction. The Tejas was awarded initial operational clearance-I (IOC-I) in January 2011. To ease up the process of FOC, an interim IOC-II was issued to Tejas in December 2013. The IOC-II expanded the g-limit, angle of attack and allowed the aircraft to carry precision guided munitions and close combat missiles. The IOC-II Tejas have an operational radius of 400–500 km (250–310 mi). The first squadron, consisting of Tejas in IOC-II configuration, became operational in 2016. The No. 45 Squadron IAF based at Sulur Air Force Station, Coimbatore was the first to have their MiG-21s replaced by Tejas aircraft at the base.

The FOC campaign began in December 2014. Two critical parameters set by IAF for FOC clearance was expansion of angle of attack from 24 degree in IOC-II to 28 degree in FOC and inflight refueling capability. In February 2018, as part of the FOC campaign, the Tejas carried out a "hot refuelling" - refuelling with engine running, which shortens the turnaround time by 30% and doubles the sortie rate. In September 2018, the Tejas successfully completed its mid-air refuelling trials required for the aircraft to obtain its FOC. In January 2019, HAL received permission from CEMILAC to start production of the FOC standard Tejas. On 20 February 2019, during the Aero India 2019 show, FOC was formally awarded to the Tejas. The HAL handed over the FOC certificate to the then Air Chief Marshal BS Dhanoa at the Yelahanka Air Force base. After the formal ceremoney, ACM Dhanoa stated that Tejas was "ready" and "behaved like a true fighter". The second Tejas squadron – No.18 Flying Bullets was formed at Sulur Air Force Station on 27 May 2020 with the first four serial production FOC aircraft. A full mission simulator (FMS) phase-1 was commissioned at Sulur Air Force Station on 23 October 2021. Phase 1 of the FMS features training in aircraft handling and full envelope flying. Phase 2 will further augment the training with focus on weapons system and advance sensors onboard Tejas.

Upgrades and further development

In May 2015, the Comptroller and Auditor General of India (CAG) noted some shortcomings in the then-delivered Tejas Mark 1 IOC standard aircraft, which according to the CAG would limit the ability to survive and operation deployment of the aircraft in actual combat. A few of these shortcomings, including lack of combat endurance, were addressed in the Tejas Mark 1 FOC configuration aircraft. Tejas Mark 1 FOC is modified to perform in-flight refuelling from Ilyushin Il-78 and Sukhoi Su-30MKI. Tejas is also undergoing butt firing trials and air-to-air firing at HAL, Nashik facility with Gryazev-Shipunov GSh-23. The shortcomings, such as the increased weight and reduced speed, would be addressed in the upcoming Tejas Mark 1A aircraft by increasing the use of composites in manufacturing and reducing the supersonic drag by using more aerodynamic pylons. The MK1A will also have AESA radar, a self-protection jammer, updated avionics and electronic warfare capabilities, among other improvements. The shortcomings identified by CAG that require redesign and structural modification such as increasing internal fuel capacity, are planned to be rectified in the Tejas Mark 2. An agreement has been signed by the Indian Air Force and the Aeronautical Development Agency to include advanced weaponry and sensors into HAL Tejas. By transferring technical know-how for the smooth integration of weapons and sensors, ADA and the IAF's Software Development Institute (SDI) hope to empower the IAF to carry out integration and flight testing on its own. On 5 March 2024, the high-altitude testing for On-Board Oxygen Generating System centric Life Support System (OBOGS-ILSS) of Tejas was successfully completed by DRDO. It could be used in MiG-29K, Tejas Mk2, AMCA, TEDBF and other aircraft with modifications. LCA PV-3 aircraft were used to test the system under a variety of flight conditions, including high g force and altitudes of up to 50,000 ft (15 km). OBOGS oxygen concentrations, demand breathing, 100% oxygen availability, and aerobatic maneuvers at the necessary altitudes for complete functional testing were carried out following CEMILAC flight approval. All of the parameters have been met by the system which will replace the earlier Liquid Oxygen System (LOX). In December 2025, the Indian Air Force inducted the indigenously developed Hybrid Brake Parachute developed by Gliders India Limited (GIL). The lightweight parachute is meant to increase landing safety in case of emergency situations like high-speed recovery and reduces landing run. The chute weighs 10 kg, spans 5.75 m and covered an area of 17 m2 and has a Uni-Cross main canopy design. It can be deployed at emergency speeds of up to 340 km/h (180 kn).

Naval variant

The Naval LCA programme was commenced in 2003. According to ADA, the Naval LCA (N-LCA) Programme was envisaged to be completed in two phases, under Phase-1 two naval prototypes were developed - the two-seat NP-1 and the single-seat NP-2, based on the Tejas Mark 1 design, to carryout carrier suitability certification and weapons integration. Under Phase 2, two single-seat prototypes were planned to be built, based on the Tejas Mark 2 design, with further design optimisation and integration of the General Electric F414 INS6 engine. The first naval prototype NP-1 was rolled out in July 2010, and made its first flight on 27 April 2012. The naval LCA has stronger landing gear to absorb the forces generated during carrier take off and arrested recovery. In December 2014, the LCA Navy successfully made its first ski-jump assisted take off from a SBTF at INS Hansa. The navy variant has a distinctive flight control law mode which allows hands-free take-off. In December 2016, the Indian Navy (IN) opted out of the programme, owing to the long delay and technical reasons – such as inadequate thrust to weight ratio of N-LCA for carrier based combat operations, and issued a fresh RFI for the procurement of 57 multi-role carrier borne fighters. Because the technologies developed for the Tejas programme will be carried over to other platforms currently being developed by the ADA, test flying was continued. In 2019, an LCA navy prototype successfully carried out the first arrested landing at the SBTF in Goa in day time and night time. As of December 2019, the Naval LCA programme completed 209 test flights, including 50 ski jump take-offs and 28 arrested landings. In January 2020, the naval prototype NP-2 successfully carried out its first arrested landing and ski-jump assisted take-off from the aircraft carrier INS Vikramaditya. In July 2020, the DRDO announced that the plan to develop an LCA Mark 2 Navy had been dropped and they were working on a new carrier-borne fighter according to the Indian Navy's multi-role carrier borne fighter requirement floated in 2016 to replace the current fleet of MIG-29K/KUB carrier-based fighters. In Aero India 2021, a new twin engine naval fighter was unveiled, the Twin Engine Deck Based Fighter (TEDBF). The experience gained in the N-LCA programme will help in the development of TEDBF. In February 2023, the naval prototype completed its maiden landing and take-off from the indigenous aircraft carrier INS Vikrant.

Tejas Mark 1A

The Mk 1A variant was first realised as a compromised variant in 2015 while Manohar Parrikar was the Defence Minister. The variant would include four major upgrades including integration of smart munitions and electronic warfare suites. This was due to the already delayed first flight schedule of Tejas Mk2 of 2022. The schedule was further delayed to 2023 (by 2021) and to 2026 (as of 2025). The Tejas Mark 1A variant has more than 40 overall improvements over the Mark 1 variant. Upgraded Mark 1A features a new avionic suite centred on EL/M-2052 AESA Radar and Uttam AESA Radar developed in-house. DARE Unified Electronic Warfare Suite (UEWS), an externally mounted self protection jammer (SPJ) for enhanced survivability, in-flight refuelling capability, Onboard Oxygen Generation System (OBOGS) developed by Defence Bioengineering and Electromedical Laboratory for endurance and an expanded weapon suite consisting of Astra BVRAAM and ASRAAM. Two ASRAAMs are intended for use on Tejas Mark 1A. The production variant will come equipped with dual-rack pylons with weapon systems integration. HAL will install in-house developed Combined Interrogator and Transponder (CIT) with digital map generator by Mission and Combat Systems R&D Centre which helps transfer the required mission map on pilot display, an upgraded IFF+ from older identification friend or foe system. To better accommodate the pilots, cockpit floor is also reshaped. The upgraded Tejas Mark 1A will have a reduced turnaround time. Tejas Mark 1A will use indigenously developed Angad electronic warfare suite and DRDO Advanced Self Protection Jammer pod. BEL will supply 20 types of locally developed critical avionics and upgrades such as Digital Flight Control Computers from ADA, Air Data Computer from DRDO, Weapon Computers from ADE, Radar Warning Receiver from Combat Aircraft Systems Development & Integration Centre, and Head-up display from Central Scientific Instruments Organisation from 2023 to 2028 for ₹2,400 crore. In order to produce the BMI Engine Bay Door for the Tejas Mark 1A, HAL and National Aerospace Laboratories inked a technology transfer agreement. For the engine bay door, where it must survive a service temperature of roughly 200 °C, NAL Advanced Composites Division is creating a manufacturing process technique that uses Carbon-BMI Prepreg to create co-cured composite structures that are very temperature resistant. On 28 March 2024, Tejas Mark 1A, equipped with the first set of Carbon-BMI Engine Bay Door assembly, successfully completed the inaugural flight from HAL facility. On 19 April 2024, ADA delivered the first batch of Secondary Flight Control of Tejas Mk 1A which consists of an indigenously designed leading-edge slat and Airbrake Control Module. These flight control systems features "state-of-the-art Servo-Valve based electro-hydraulic servo actuators and control modules." The development was the result of the collaboration between ADA, Research Centre Imarat, and Central Manufacturing Technology Institute. The technology is ready to be integrated with production variants of Tejas Mk 1A as it successfully completed flight trials. These are being produced at HAL Accessories Division in Lucknow. On 30 May 2025, the first centre fuselage assembly for the Tejas Mk 1A was handed over to HAL by subcontractor VEM Technologies in Hyderabad. Milestones

According to HAL Chairman and Director R Madhavan, the design activity of Tejas Mark 1A is moving ahead, and the testing of subsystems will be completed by 2021. The taxi trials will commence in the first half of 2022, and the first flight of Mark 1A prototype will happen in the second half of 2022. On 20 May 2022, the Tejas Mark 1A prototype completed its first flight. HAL intends to obtain a certificate from Centre for Military Airworthiness and Certification (CEMILAC) within 30 months before this version enters mass production. On 28 March 2024, the first production series Mark 1A aircraft (LA 5033) conducted its inaugural flight which lasted for 18 minutes. The aircraft will undergo more testing before being officially transferred to the IAF. On 12 March 2025, Astra Mk-1 successfully demonstrated a direct hit on a flying target from Tejas. This was a significant test for Mark 1A induction.

Tejas Mark 2

The HAL Tejas design has been further developed into the Tejas Mark 2, incorporating a more powerful General Electric F414 INS6 engine, canards and other design changes. The Tejas Mark 2, which is expected to be rolled out in 2025, will have an increased payload carrying capacity and internal fuel capacity, more external hardpoints, improved combat range, a completely redesigned cockpit, and an integrated infrared search and track (IRST) system, in addition to the AESA radar. The Defence Institute of Advanced Technology (DIAT) is developing aircraft health and usage monitoring systems (HUMS) to integrate the various sensors on board the Tejas Mark 2. The first flight of Tejas Mark 2 is expected to be in late 2025 or early 2026.

Program costs

==== Development costs ==== LCA Programme - ₹9,063.96 crore (equivalent to ₹120 billion or US$1.2 billion in 2026) (up to March 2020) Kaveri engine programme - ₹2,032 crore (equivalent to ₹26 billion or US$270 million in 2026) ₹1,202 crore (equivalent to ₹15 billion or US$150 million in 2026) additional design and development (Jan 2021)

==== Flyaway costs ==== ₹146.2 crore (equivalent to ₹255 crore or US$26 million in 2026) for IOC Mark 1 (2014) ₹156 crore (equivalent to ₹382 crore or US$40 million in 2026) for FOC Mark 1 (2010) ₹303 crore (equivalent to ₹371 crore or US$39 million in 2026) for Mark 1A and ₹309 crore (equivalent to ₹378 crore or US$39 million in 2026) for export variant (2021)

Design

=== Overview === The Tejas is a single-engine multirole combat aircraft which has a tailless, compound delta wing design with "relaxed static stability" for enhanced manoeuvrability and agility. The Tejas is a multi-role combat aircraft and its flexibility permits it to carry out Interception, air-to-surface and anti-shipping roles in a single mission. The wind tunnel testing and computational fluid dynamics analysis have optimised the design of Tejas for minimum transonic and supersonic wave drag, as well low wing-loading.

Tejas has eight hardpoints – one beneath the port-side air-intake, one under the fuselage (centreline station) and three hardpoints under each wing, of these, three are wet hardpoints which can carry drop tanks. The hardpoint beneath the port side air-intake is dedicated to carrying sensor pods such as FLIR, IRST or laser rangefinder/designator. These can also be carried on the centreline pylon and inboard pairs of wing stations. It has an aerial refuelling probe on the starboard side of the forward fuselage. The Tejas weapon suite consists of I-Derby ER and Astra beyond visual range air-to-air missiles and R-73, Python-5 and ASRAAM close combat missiles. The Tejas has an internal 23 mm Gryazev-Shipunov GSh-23 twin-barreled autocannon under the starboard side air-intake. The BrahMos-NG supersonic cruise missile is being developed for the Tejas. The relatively smaller size, extensive use of airframe composites, the Y-duct inlet which shields the engine compressor blades, the application of radar-absorbent material (RAM) coatings and so on, reduces the overall radar cross-section of the aircraft.

=== Airframe === Apart from aluminium-lithium alloys and titanium alloys, carbon-fibre composite materials are used in the construction of the Tejas. The composite materials constitute 45% of the airframe by weight and 90% by surface area, the highest among contemporary aircraft. The upper and lower wing surfaces, wing spars and wing ribs are also made out of carbon-fibre composites, while the fin tip is made out of fiberglass. The extensive use of composite materials in the airframe not only makes the aircraft lighter but also gives high strength. This also reduces the number of joints or rivets, increases the aircraft's structural integrity and lowers its susceptibility to fatigue cracks. The tailfin is a monolithic honeycomb structure, reducing the manufacturing cost by 80% compared to traditional methods. Initially, the Tejas prototypes were equipped with a radome made out of Kevlar which was replaced with a quartz radome in the production aircraft. In July 2026, it was confirmed that the R&DE(E) of DRDO has completed the development of an indigenous quartz radome for LCA Mk1A and has successfully underwent all necessary structural, mechanical and electromagnetic performance trials and is now ready for transfer to industry for production. The final evaluation under flight trials are underway. The radomes were so far sourced from Cobham Limited. The naval LCA has a nose droop to provide improved view for carrier landings. In addition to the elevons, the naval LCA has wing leading–edge vortex controllers (LEVCON) control surfaces that extend from the wing-root leading edge, which could be deflected to a downward angle or an upward angle to increase lift and reduce airspeed during approach. The LEVCONs also provides better low-speed handling and increase controllability at high angles of attack (AoA). The naval Tejas also has a strengthened undercarriage, stronger landing gear, and an arrestor hook system for carrier landings. The two-seat LCA Navy variant (NP-1) have aerodynamic commonality with the trainer variant. The Secondary Flight Control of Tejas Mk 1A consists of an indigenously designed Leading Edge Slats and Airbrake Control Module. Aeronautical Development Agency, on 19 April 2024, delivered the first batch of these flight control system. These flight control systems features "state-of-the-art Servo-Valve based electro-hydraulic servo actuators and control modules." The technology is ready to be integrated with production variants of Tejas Mk 1A as it successfully completed flight trials. These are being produced at Accessories Division, HAL, Lucknow.

=== Avionics === The avionics of the Tejas Mark 1 is centered around the Elta EL/M-2032 radar. Its digital flight control computer developed by ADE and manufactured BEL. It has an electronic warfare (EW) suite domestically developed by Defence Avionics Research Establishment, which consists of a radar warning receiver (RWR), integrated self-protection jammer, chaff and flare dispenser system. The Tejas Mark 1A variants are equipped with an AESA radar, a new high performance digital flight control computer (DFCC Mk1A), new EW suite and updated avionics. Some of the production Mark 1A fighters will be equipped with the Elta EL/M-2052 AESA radar, while rest of the aircraft are expected to fly with the domestically developed Uttam AESA Radar. The new EW system for the Mark 1A, developed by DARE known as the Unified Electronic Warfare suite (UEWS), will have electronic countermeasures and electronic counter-countermeasure capabilities, digital radio frequency memory based jamming and deception capabilities. The Tejas Mark 1A will also carry a pod-mounted self-protection jammer – the Elta ELL-8222WB. The Mark 1A will have software-defined radio-based secure communications and network-centric warfare capabilities.

The Tejas can also carry pod-based sensors such as forward looking infrared (FLIR). Currently the Tejas is cleared to carry the Rafael Litening III targeting/reconnaissance pod, while an advanced version named Litening 4I will be integrated on the Tejas. The Litening 4I pod, developed by the C4I systems division of Rafael, enables the aircraft to carry out reconnaissance, surveillance and intelligence gathering, in addition to target acquisition. The Tejas has an integrated health-monitoring system. The Tejas has a night vision goggles compatible glass cockpit, equipped with a domestically developed HUD, three multi-function displays, two Smart Standby Displays by CSIO. The Tejas has hands-on-throttle-and-stick arrangement to reduce pilot's workload. The displays provide key information on a need-to-know basis, the pilot interacts with onboard systems through a multi-functional keyboard and several selection panels. The Tejas has a "get-you-home" panel coupled with an air data computer developed by Bharat Electronics Limited to assist the pilot in case of an emergency. The cockpit is equipped with Martin-Baker 16LG zero-zero ejection seat and canopy severance system developed by DRDO's ARDE and HEMRL for safe ejection. For life support, Tejas Mark 1 relies on conventional liquid oxygen LOX system, while an onboard oxygen-generation system (OBOGS) has been developed for Tejas Mark 1A. The ADA has developed virtual reality assisted cockpit simulator for Tejas, and N-LCA. Currently Tejas pilots are flying with Elbit DASH IV helmet-mounted display system. The DRDO-developed fighter aircraft escape system has passed the high-speed rocket-sled test at controlled did at the Rail Track Rocket Sled facility of the TBRL in Chandigarh in December 2025. Tejas Mk 1A's Swayam Raksha Kavach EW package, which includes the Advanced Self Protection Jammer pod and the Dhruti DR118 RWR, is based on the D-29 EW Suite developed for the MiG-29. The RWR has four channel wide band receivers, which enhance the possibility of detecting and precisely determining the direction of enemy airborne and ground-based radars. The LSP-3 (KH2013) aircraft was used to test the SRK EW suite for an integrated mode of operation with internal RWR sensor and the ASPJ pod. It included a restricted multi-emitter test scenario for ground and aerial radar jamming. In 2023, several tests and sorties were carried out to check the integration of the SRK EW suite with Uttam radar. As of 30 October 2025, the EW suite is undergoing flight trials which is scheduled to conclude by mid-2026. Development of the system started in 2021, and deployment is anticipated by the end of 2026. While the RWR is integrated within the aircraft, the ASPJ pod will be mounted on a hardpoint.

Flight control system

The aerodynamic configuration of Tejas is based on a delta-wing layout with shoulder-mounted wings. The control surfaces include three-section slats on the wing's outer leading edge while the inboard sections of the wings have additional slats to generate vortex lift over the inner wing and high-energy air-flow along the tail fin to enhance high-AoA stability. The wing trailing edge fits two-segment elevons to provide pitch and roll control. The only empennage-mounted control surfaces are the single-piece rudder and two airbrakes, located in the upper rear part of the fuselage, one each on either side of the fin. Since the Tejas is a relaxed static stability design, it is equipped with a NAL-developed full authority quadruplex digital fly-by-wire flight control system and an open architecture digital flight control computer developed by BEL. Its flight control surfaces are controlled by hybrid electro-hydraulic actuators through the digital flight control computer. The fly-by-wire flight control system of the Tejas has an advanced feature called auto low-speed recovery. This enables envelope protection at low speed and high angles of attack. It prevents the aircraft from entering into uncontrolled flight while maneuvering. Another feature is disorientation recovery function, once engaged it will recover the aircraft to an optimal altitude, airspeed and level flight. Some of the flight control laws for these features were formulated by the IIT Bombay research university. On 19 February 2024, Tejas Mark-1A prototype LSP-7 successfully completed sortie with indigenously designed high performance Digital Flight Control Computer. The system was developed by Aeronautical Development Establishment (ADE). The latest DFCC has a quadraplex PowerPC-based processor, a fast I/O controller based on an autonomous state machine, increased computational throughput, and sophisticated on-board software that satisfies DO-178C level-A safety regulations. All important metrics and the flight controls' performance were deemed adequate during the flying test.

Propulsion

Developing an indigenous jet engine for Tejas was one of the five self-reliance goals identified at the beginning of the LCA Programme. A programme led by the Gas Turbine Research Establishment (GTRE) to design and develop an indigenous powerplant, the Kaveri, was launched as early as in 1986. However Kaveri jet engine development faced some setbacks, hence the General Electric F404-GE-F2J3 afterburning turbofan engine was procured as an interim solution. Ten units of the F404-F2J3 engine power the Technology Demonstrator and Prototype variants of Tejas. Since 2004, uprated General Electric F404-GE-IN20 engines are being used on LSP, Naval prototypes and Mark 1 variants of Tejas. The production Tejas Mark 1 is powered by the F404-IN20 engine, with the same power-plant intended to power Mark 1A variant also, while the heavier Tejas Mark 2 will be powered by a General Electric F414-INS6 engine.

Serial production

=== Orders === First Tejas Mk1 contract (total 20 jets): 31 March 2006 — Indian Government on behalf of the Indian Air Force placed an initial order for 20 LCA Tejas, from HAL, for delivery by December 2011. The order comprised 4 twin seat trainers, and 16 single seat Tejas IOC II. September 2024 — The delivery, scheduled for completion in 2011, was finally completed. Second Tejas Mk1 contract (total 20 jets): 23 December 2010 — Indian Government ordered 20 additional LCA Tejas, comprising 4 twin seat trainers, and 16 single seat Tejas FOC bringing the total aircraft to 40. It was to be delivered by December 2016 at a cost of ₹5,989.39 crore (US$1.31 billion). 27 March 2025 — The contract value was revised to ₹6,542.20 crore (equivalent to ₹68 billion or US$700 million in 2026). 10 January 2025 — 38 of the 40 aircraft were delivered and the last two trainers would be delivered soon. 11 January 2025 — The last of the 40 Tejas aircraft - LT-5208 - took its first flight. 5 February 2025 — The final two of the trainers were yet to be delivered owing to not meeting the service requirements. 11 September 2026 — The final two trainers were reported to be ready for delivery. 18 September 2026 — The seventh and eighth trainers were delivered to the Indian Air Force which completed the first two Tejas orders placed in 2006 and 2010, respectively. First Tejas Mk 1A 2021 contract (total 83 jets): August 2018 — The Defence Acquisition Council accorded Acceptance of Necessity for procurement of 73 Tejas Mk 1A aircraft with active electronically scanned array radar, beyond-visual-range missile, self-protection jammer, and aerial refueling capabilities. The rest of 10 trainer aircraft would be of Tejas Mk1 standard. 13 January 2021 — Cabinet Committee on Security cleared the procurement of 73 Tejas Mk 1A single seater and 10 Tejas Mk 1 twin seater trainer at the cost of ₹45,696 crore (equivalent to ₹560 billion or US$5.8 billion in 2026) with additional funds for Design & Development and Infrastructure worth ₹1,202 crore (equivalent to ₹15 billion or US$150 million in 2026). 3 February 2021 — Ministry of Defence signed the contract with HAL on the inaugural day of Aero India 2021 at a cost of almost ₹48,000 crore (equivalent to ₹590 billion or US$6.1 billion in 2026). 17 August 2021 — HAL signed a contract with GE worth ₹5,375 crore (equivalent to ₹66 billion or US$680 million in 2026) to supply 99 F404 engines and service support by 2029. Second Tejas Mk 1A contract (total 97 jets): 16 September 2023 — Air Chief Marshal VR Chaudhari stated that the IAF has decided to order 97 more Mark 1A fighter jets including 29 Tejas Mk 1A standard trainer jets. 30 November 2023 — The Defence Acquisition Council accorded Acceptance of Necessity for procurement of additional 97 Tejas Mk 1A for IAF from Hindustan Aeronautics Limited under Buy (Indian-IDDM) category 12 April 2024 — MoD issued ₹65,000 crore (equivalent to ₹690 billion or US$7.2 billion in 2026) tender to HAL for 97 Tejas Mark 1A fighter jets. Clearance for the deal expected to be received from CCS in December 2024 and deal to be signed by year-end. August 2025 — Negotiations for additional F404 engines is expected to be completed this month, while the contract for 97 Tejas Mark 1A was cleared by the CCS on 19 August 2025 for ₹66,500 crore (equivalent to ₹690 billion or US$7.1 billion in 2026). 25 September 2025 — The agreement was signed one day prior to the retirement of MiG-21 on 26 September and was valued at ₹62,370 crore (equivalent to ₹660 billion or US$6.9 billion in 2026). Along with related equipment, the 97 jets would consist of 29 twin-seaters and 68 fighters. The delivery is expected to start in 2027–2028 and conclude in the next six years. In comparison to the 2021 deal, this order will include 67 additional items and more than 64% indigenous content. These jets will incorporate control surface actuators, Swayam Raksha Kavach EW Suite, and Uttam AESA Radar. Around 40 components being imported for the 2021 deal are expected to be indigenised for the 97-jet contract. October 2025 — HAL is expected to place an additional order for 113 F404 engines worth $1 billion this month. The contract signing was earlier expected in September. 7 November 2025 — A contract for 113 F404 engines and the related support package, valued at about ₹8,870 crore (US$921 million), was signed. Delivery are scheduled to start in 2027 and will conclude by 2032. Delivery schedule — As per a report by Moneycontrol on 19 November 2025, the first batch of eight Mark 1A aircraft is expected to be delivered within the next 24–36 months. Additionally, HAL plans to deliver three major tranche of 24 aircraft to be delivered following months 37, 49 and 61 with the final batch of 12 aircraft to be delivered between month 73 and 84. Hence, the delivery timeline is expected to end in late 2032. 31 July 2026 — HAL placed an order for 122 Active Antenna Array Units and 121 Interface Frames for the Uttam AESA Radar with Astra Microwave Products Limited on 31 July 2026, for ₹2,205 crore (US$230 million).

=== Production lines === Bengaluru Plant I: HAL's first Tejas production line is situated at Bangalore near HAL Airport. The production line was set up at a cost of ₹1,556 crore (equivalent to ₹27 billion or US$280 million in 2026), with HAL holding 50% stake and the rest held by IAF and Navy. First serial production aircraft delivered in 2015 with production rate of 8 per year. Bengaluru Plant II: In March 2017, Government of India sanctioned ₹1,381.04 crore (equivalent to ₹21 billion or US$220 million in 2026) for setting up an additional production line under Aircraft Division, HAL. This would increase the production capacity from 8 to 16. Production of sub-components like Front Fuselage, Centre Fuselage, Rear Fuselage, Wings were outsourced to private partners. The production plant was inaugurated by the Defence Minister, Rajnath Singh, on 2 February 2021. Nashik Plant: On 5 April 2023, the then Defence Secretary, Giridhar Aramane, laid the foundation stone for a third production line at HAL, Nashik with an investment of over ₹150 crore (equivalent to ₹164 crore or US$17 million in 2026). This would bring the total production capacity from 16 to 24 aircraft annually. The production of aircraft at this plant would start from October 2024 with the first example then expected by the end of April 2025. The first Tejas Mk 1A took its first flight on 17 October 2024 after being inaugurated by the Defence Minister, Rajnath Singh. The facility is spread on 1,300,000 sq ft (120,000 m2) and employs 30 structural assembly jigs for all major aircraft modules like the centre fuselage, front fuselage, rear fuselage, wings and air intake. The facility outsources 40% of its workshare to private firms and plans to enhance annual aircraft output to 10 in two years. Nashik Plant II: HAL also plans to setup another production line at Nashik to ramp up production capacity from 24 to 32 as reported on 10 January 2025. The line can start production within one and a half years of sanction. The establishment of the plant is subject to a regular supply of GE engines.

Delivery

==== Mark 1 contracts ==== On 1 October 2014, LCA-SP1 aircraft took the first flight. On 17 January 2015, the aircraft was delivered to the Indian Air Force. Left head till then flow on 5 sorties to test various equipment. Due to delays in production the cost per aircraft rose from ₹120 crore (equivalent to ₹421 crore or US$44 million in 2026) in 2006 to ₹160 crore (equivalent to ₹263 crore or US$27 million in 2026) in 2015. However, the aircraft was not inducted into a squadron till 2016 until sufficient numbers were delivered by HAL. The aircraft would also require additional flight hours before induction. Expected delivery timeline was as follows: SP-2 in March, up to SP-5 by June, up to SP-8 by March 2016; completing a total of 8 aircraft. The formation of the first Tejas-equipped squadron started in July 2011. No. 45 Squadron IAF (Flying Daggers), the first Tejas squadron, was operationalised in July 2016. It is based in Sulur Air Force Station, Coimbatore. When the first order was placed in 2006, it was expected that ADA would receive Initial Operational Clearance (IOC) by 2008. Induction was scheduled by December 2011. However, IOC was originally received in December 2013 and the first IOC variant was delivered in FY2016-17. As of 11 February 2019, 12 IOC aircraft were delivered with 4 due to be delivered by March 2019. Also, on 31 December 2018, ADA has handed over Drawing Applicability List (DAL) and Equipment Standard of Preparation (SOP) documents, for FOC configuration to HAL for production. The production and delivery of 8 Tejas Trainer would start after design clearance by ADA. The second Tejas Mark 1 squadron, Squadron 18, was formed at Sulur on 27 May 2020. The first front fuselage of Tejas Mk1 FOC aircraft for the second order was delivered by Dynamatic Technologies on 2 November 2020. By August 2023, the delivery of all 32 single-seat Tejas Mk 1 aircraft (IOC and FOC) were completed.