The Tejas Mark (Mk) 1 is a 4.5 generation, lightweight, high-agility supersonic multi-role fighter aircraft that officially entered service with the Indian Air Force (IAF) in July 2016. Designed and developed by the Defence Research and Development Organisation’s (DRDO) Aeronautical Development Agency (ADA) under the ambitious Light Combat Aircraft (LCA) programme, Tejas represents a significant leap for India’s indigenous aerospace capabilities. Hindustan Aeronautics Limited (HAL) serves as the prime industrial contractor for the project.
Recognizing the potential for further enhancement, ADA signed a memorandum of understanding (MOU) with the IAF in February 2024 to integrate futuristic weapons and sensors into the Tejas aircraft. Further demonstrating progress in self-reliance, ADA handed over the first batch of indigenously produced leading-edge actuators and airbrake control modules to HAL in April 2024. These units are slated for production by HAL to fulfill the order for 83 Tejas Mk1A aircraft, the improved version of the Tejas Mk1, pending production clearance. HAL is actively preparing its facilities for this significant production run.
Development Timeline and Milestones
The journey of the Tejas began with the LCA programme’s first demonstrator aircraft, which conducted its maiden flight in January 2001, followed by a second in June 2002. The series production version achieved its first flight in April 2007, and the trainer variant took to the skies in November 2009. Subsequent limited series production (LSP) models, including LSP-4 and LSP-5, had their inaugural flights in June and November 2010, respectively. The aircraft achieved Initial Operational Clearance (IOC) certification in January 2011, following successful testing in December 2010.
Further prototypes, LSP-7 and LSP-8, flew in March 2012 and 2013. A crucial step in its combat readiness, Tejas successfully fired an infrared-seeking air-to-air missile in December 2013, coinciding with the achievement of IOC status. During this period, a prototype equipped with an advanced electronic warfare (EW) suite developed by the DRDO also commenced flight testing.
The first series-production aircraft made its maiden flight in October 2014 and was officially delivered to the IAF in January 2015. The second series-production (SP2) aircraft followed suit in March 2016. Diversifying its operational capabilities, the naval variant of Tejas conducted its first flight in April 2012 and successfully completed rigorous test flights on the INS Vikramaditya aircraft carrier in January 2020. The formal induction of the first two Tejas aircraft into the IAF occurred in July 2016. The Tejas Mk1, in its Final Operational Clearance (FOC) configuration, was formally inducted into service in May 2020. Marking progress on the improved variant, HAL completed the first flight of the Tejas Mk1A in March 2024.
Conceptual Design and Flight Testing
Designed as an all-weather, tactical fighter, the Tejas is available in both single-seat fighter and two-seat training configurations. A carrier-borne version, featuring modifications such as a strengthened landing gear, a modified nose, and an arrestor hook, received design approval in 1999. This naval variant also incorporates retractable canards and adjustable vortex control surfaces. The Indian Government initiated a dedicated development programme for carrier-borne Tejas versions in 2002, leading to the first flights of two prototype aircraft in 2009.
Hot weather flight trials, a critical aspect of testing, were conducted by the IAF in June 2010. These trials evaluated the performance of the digital flight control computer, various avionics systems, the multimode radar, radar warning receiver (RWR), and the electrical and environmental control systems under temperatures reaching up to 45°C. Demonstrating its offensive capabilities, the Tejas LSP-7 prototype successfully conducted a test firing of the indigenous Astra beyond visual range air-to-air missile (BVR-AAM) from an altitude of 20,000ft off the coast of Goa in August 2023. The Tejas Mk1A programme reached a significant milestone in February 2024 with the successful flight of LSP7, which integrated the indigenously developed quadruplex digital fly-by-wire flight control computer (DFCC), featuring enhanced processing power and stringent safety standards.
Tejas Mk1 Design and Features
The Tejas Mk1 features a distinctive delta wing platform design with shoulder-mounted delta wings. It includes a single fin but notably lacks a horizontal tail plane, contributing to its agility. The aircraft has an approximate empty weight of 5,450kg and a maximum take-off weight of 13,500kg. Its construction extensively utilises lightweight materials, including alloys of aluminium, lithium, and titanium, alongside carbon composites. The wing structure specifically incorporates composite spars and ribs, covered by a carbon fibre-reinforced plastic skin, highlighting the use of advanced materials in its design.
The aircraft is equipped with nine external hardpoints located on the wings and fuselage, enabling it to carry a diverse range of equipment and weapons. In addition to ordnance, these hardpoints can accommodate pods for electronic warfare (EW), targeting, surveillance, reconnaissance, or training purposes. The Tejas Mk1A variant includes an in-flight refuelling probe on the front starboard side for aerial refuelling capabilities. Furthermore, the aircraft can carry external drop tanks with a capacity of up to 4,000 liters on the inner and mid-board wing hardpoints and the fuselage centreline hardpoint, significantly extending its range.
Cockpit and Avionics
The Tejas Mk1 features a modern, night vision-compatible glass cockpit equipped with zero-zero ejection seats supplied by Martin Baker (UK) for pilot safety. The primary displays include dual 76mm × 76mm colour multifunction displays provided by Bharat Electronics. A head-up display, developed by the government-owned Central Scientific Instruments Organisation (CSIO), is also integrated, along with a liquid crystal return-to-home-base panel incorporating a keyboard.
Enhancing pilot awareness and reducing workload, the cockpit design incorporates a helmet-mounted display and sight (HMDS) and a hands-on throttle and stick (HOTAS) system. For navigation, Tejas integrates a Sagem SIGMA 95N ring laser gyroscope inertial navigation system complemented by GPS capabilities. Its communication suite is comprehensive, featuring VHF to UHF radios with counter-countermeasures, data links for air-to-air and air-to-ground operations, and a HAL-developed friend-or-foe interrogator. Additional systems include an environmental control system from Spectrum Infotech. The avionics suite encompasses a health-monitoring system, ground proximity and terrain-referenced navigation, instrument landing system, GPS, a stores management system, and three 1553B 32-bit mission computers. The secondary flight control systems, managing leading-edge slats and airbrakes, utilise Servo valve-based electro-hydraulic actuators and control modules, contributing to enhanced flight control and pilot comfort.
Weapons and Countermeasures
For close-range combat, the Tejas is equipped with a 23mm twin-barrelled GSh-23 gun, mounted in a blister fairing under the starboard air intake. This gun boasts a high burst firing rate of 50 rounds per second and a muzzle velocity of 715m per second. The aircraft’s external hardpoints allow it to be armed with a variety of ordnance. This includes air-to-air missiles such as the Vympel R-73 for within visual range engagements, as well as air-to-ground and anti-ship missiles for attacking surface targets. It can also carry precision-guided munitions, rockets, and conventional bombs. To enhance its beyond visual range capabilities, the Derby BVR-AAM was procured from Rafael Advanced Defence Systems, intended for integration on 200 aircraft. The Derby missile is capable of engaging targets at ranges up to 50km.
Sensors and Radar
The Tejas Mk1 features a multimode radar housed within a Kevlar radome. This radar supports multiple operational modes including target search, track-while-scan, and ground mapping. It functions as a pulse Doppler radar with advanced capabilities such as Doppler beam shaping, moving target indication, and look-up/look-down capability to track targets at different altitudes.
The improved Mk1A variant significantly upgrades the sensor package. It incorporates airborne electronically scanned array (AESA) fighter radar technology, providing enhanced detection range, multiple target engagement capability, and resistance to electronic jamming. The Mk1A also includes an advanced EW suite comprising a radar warning receiver and jammer, a laser warner, a missile approach warner, and chaff and flare dispensers for self-protection against incoming threats. Other advanced features on the Mk1A include a digital map generator (DMG), smart multi-function displays (SMFD), a combined interrogator and transponder (CIT), and an advanced radio altimeter, further enhancing the aircraft’s situational awareness and operational effectiveness. Comparing the sensor capabilities helps understand the difference between 4th and 5th generation fighter aircraft.
Engine and Performance
The Tejas is powered by GE Aerospace’s F404-GE-IN20 turbofan engine. This robust engine delivers a thrust of 19,000lb and boasts an airflow rate of 153lb/s, providing the necessary power for the Tejas’s performance characteristics. For engine start-up on the ground, the aircraft is fitted with a HAL-developed gas turbine starter unit model GTSU-110, which supplies the required airflow and power to initiate the main engine’s startup sequence.
The Tejas aircraft is capable of achieving a maximum speed of Mach 1.6 (equivalent to approximately 1,975km/h) at high altitudes. Its maximum operational altitude is 15,240 meters (50,000 feet). The aircraft offers a respectable ferry range of 3,000km, allowing it to cover significant distances when fitted with external fuel tanks. Understanding such performance metrics is key when considering the capabilities of modern military aircraft, and perhaps even comparing them against a top 10 fighter aircraft list.
Orders and Deliveries
Hindustan Aeronautics Limited (HAL) has received substantial orders from the Indian Air Force for the LCA Tejas programme. Initially, orders were placed for a total of 40 aircraft, comprising 20 aircraft in the Initial Operational Clearance (IOC) standard and 20 in the Final Operational Clearance (FOC) standard. The IOC contract, signed in March 2006, was valued at Rs28.1bn ($631m), with an amendment later sought for Rs53.6bn ($1.2bn) for additional components. The FOC contract was signed in December 2010, with a value of Rs59.8bn ($1.3bn).
A major contract was awarded by the government to HAL in February 2021 for the production and delivery of 83 Tejas aircraft. This order specifically includes 73 of the improved Tejas Mk-1A fighter aircraft and ten Tejas Mk-1 trainer aircraft. This contract is valued at a significant Rs480bn ($6.5bn). HAL is scheduled to deliver all 83 aircraft within an eight-year timeframe from the contract signing. In October 2023, the IAF took delivery of a twin-seater LCA Tejas variant, further bolstering its training capabilities.
Tejas Mk2 Variant Development
Building on the success of the Tejas Mk1 and Mk1A, ADA is currently developing the Tejas Mk2. This future variant is envisioned as a medium-combat aircraft and represents a further advancement in India’s indigenous fighter development efforts. The Mk2 is expected to be a more advanced version, potentially incorporating enhanced stealth features and a more powerful engine configuration compared to its predecessors. Early concepts suggest it might feature two engines with fully vectoring nozzles and a tailless design, aiming for increased maneuverability and reduced radar cross-section.
The first flight of the Tejas Mk2 variant is currently anticipated in 2025. This aircraft is intended to serve as a replacement for the IAF’s aging fleets of Jaguar and Mirage 2000 aircraft, providing a significant upgrade in capabilities and operational effectiveness. Understanding the development of aircraft like the Tejas Mk2 provides insight into how future generations of fighter aircraft 5th generation fighter aircraft will fly. The Mk2’s projected capabilities position it as a potential bridge towards or include features found in a 4.5th generation fighter aircraft.
Key Contractors Involved
The development and production of the Indian Fighter Aircraft Tejas involve numerous key contractors, primarily from India’s defence and aerospace sector. Hindustan Aeronautics Limited (HAL) serves as the prime industrial contractor responsible for manufacturing the aircraft. Bharat Electronics (BEL), a government-owned aerospace and defence company, plays a crucial role, having been awarded a Rs24bn ($315.8m) contract by HAL in December 2021 to supply 20 different varieties of airborne electronic systems specifically for the Tejas Mk1A variant.
The aircraft’s sophisticated electronic warfare suite was developed by the Advanced Systems Integration and Evaluation Organisation (ASIEO), an agency based in India dedicated to advanced systems integration. National Aerospace Laboratories (NAL) contributed significantly to the airframe, designing and producing the fin and the rudder, and also undertaking construction of the aircraft fuselage. The Digital Fly-by-Wire Flight Control Computer (DFCC) for the Tejas Mk1A was developed by the Aeronautical Development Establishment (ADE), a laboratory under DRDO. The aircraft’s multimode radar was a collaborative effort, jointly developed by the Electronics Research and Development Establishment, another DRDO laboratory, and HAL. While primarily an indigenous effort, international collaboration exists, such as Saab, an aerospace and defence company from Sweden, which offered a sensor package solution for the Mk1A aircraft, demonstrating the complex web of suppliers involved in modern fighter jet development.
Conclusion
The Indian Fighter Aircraft Tejas represents a monumental achievement for India’s defence and aerospace industry, demonstrating its capability to design, develop, and manufacture a modern, multi-role supersonic combat aircraft. From its challenging development phase under the LCA programme to the entry into service of the Mk1 variant and the ongoing production of the improved Mk1A, Tejas has steadily evolved. With plans for the more advanced Mk2 variant underway, aimed at replacing older aircraft fleets, the Tejas programme continues to be a cornerstone of India’s quest for self-reliance in defence manufacturing. Its operational capabilities, indigenous systems integration, and ongoing development efforts position the Tejas as a significant asset for the Indian Air Force, enhancing its operational readiness and technological edge.
