The HAL Tejas Mk1A is the production-improved variant of India’s indigenous Light Combat Aircraft (LCA), a single-engine, tailless compound-delta multirole fighter designed to replace the Indian Air Force’s ageing MiG-21 fleet. Building on the baseline Tejas Mk1 inducted from 2016, the Mk1A adds an AESA radar, a modernised electronic-warfare suite, and improved beyond-visual-range weapons integration, and forms the centrepiece of a 180-aircraft order intended to significantly expand India’s indigenous fighter fleet through the late 2020s.[1]
India launched the LCA programme in 1983 to design a modern successor to the MiG-21, establishing the Aeronautical Development Agency (ADA) in 1984 as the nodal body overseeing development.[2] The aircraft, later named Tejas (“radiance”), made its first flight on 4 January 2001, following an unusually long design and testing phase shaped by sanctions-driven technology restrictions and the need to develop several critical indigenous sub-systems from scratch.[2] Initial Operational Clearance (IOC-I) was awarded in January 2011, with an interim IOC-II following in December 2013, and Final Operational Clearance (FOC) was granted in November 2019, nearly two decades after first flight.[2] The baseline Tejas Mk1 was inducted into No. 45 Squadron “Flying Daggers” at Sulur Air Force Station, replacing that unit’s MiG-21s, though it took more than three further years for the squadron to reach its full complement of 16 fighters.[6] The improved Mk1A standard was contracted in a ₹48,000 crore deal for 83 aircraft signed in 2021, later expanded with a further 97-aircraft order to bring the total Mk1A order book to 180 jets.[1]
The Tejas is a tailless, compound-delta-wing, single-engine fighter powered by a General Electric F404-GE-IN20 turbofan (F404-IN20 on the Mk1A), giving a maximum speed of Mach 1.8 and a service ceiling of roughly 52,500 feet (16,000 m).[9] The delta configuration provides strong high-angle-of-attack performance relative to conventional-wing fighters, while the aircraft’s compact size and light weight give it a favourable thrust-to-weight ratio for its class.[9] Operational radius on the IOC-II-standard baseline aircraft is roughly 400-500 km, and the type carries a 23 mm twin-barrel GSh-23 cannon with a burst rate of about 50 rounds per second, alongside precision-guided munitions and close-combat and beyond-visual-range air-to-air missiles across multiple external hardpoints.[9] The Mk1A specifically adds an indigenous Uttam AESA radar, a self-protection electronic-warfare suite, aerial refuelling capability, and improved maintainability intended to raise fleet-wide serviceability rates over the Mk1.[1]
Delivery of the Mk1A has been substantially delayed by supply-chain problems with its F404-IN20 engines. As of early 2026, HAL had manufactured, flown, and flight-tested roughly 30 Mk1A airframes (fighters and trainers combined) using interim “Category-B” engines for trials, but these aircraft remained parked awaiting combat-standard F404-IN20 powerplants from GE Aerospace before formal handover to the IAF could begin.[4] The first of 99 contracted F404-IN20 engines rolled out from GE’s factory on 25 March 2025, with GE and HAL targeting a cadence of roughly 12 engines delivered in 2025, rising to about 20 per year from 2026.[1] HAL’s chairman indicated during the company’s Q4 FY26 earnings call that formal Mk1A deliveries to the IAF were expected to begin between August and September 2026, contingent on the engine supply reaching a steady state.[7] A sixth F404 engine was expected at HAL in January, part of the gradually improving delivery cadence intended to unlock the backlog of completed but un-powered airframes.[8]
The programme spans the baseline Tejas Mk1 (inducted 2016, IOC-II/FOC standard), the improved Tejas Mk1A (AESA radar, EW suite, aerial refuelling, 180 on order), and the twin-seat trainer variants used for conversion training, alongside the separately developed, larger Tejas Mk2 under parallel development as a heavier, more capable follow-on.[1]
The current Mk1A order comprises an initial 83-aircraft contract worth ₹48,000 crore signed in 2021, subsequently expanded by a further 97 aircraft to bring the total order to 180 jets, alongside a separate 99-engine F404-IN20 contract with GE Aerospace to power the fleet.[1] The scale of the combined order represents one of the largest indigenous fighter-aircraft commitments in Indian Air Force history, intended to significantly expand India’s home-built fighter inventory even as engine-supply delays have pushed actual squadron deliveries several years behind the original schedule.[4]
The Tejas programme has drawn sustained criticism over its multi-decade development timeline, running from a 1983 programme launch to a 2019 Final Operational Clearance, and the Mk1A phase has faced further, well-documented delays tied to GE Aerospace’s F404-IN20 engine supply chain, radar integration, and weapons-certification challenges, with HAL’s own leadership publicly acknowledging that dozens of completed airframes sat parked awaiting engines through 2025 and into 2026.[4] Reviews of the Mk1A programme’s schedule have been repeatedly pushed back, reported in some cases moving key milestones to June and then later dates as radar, engine, and weapons-integration issues compounded.[3] Supporters of the programme note that the delays are substantially attributable to a single foreign engine supplier’s production constraints rather than indigenous design failures, and that the eventual 180-aircraft fleet will still represent a major expansion of India’s home-built combat-aircraft capacity once deliveries stabilise.[7]
The baseline Tejas Mk1 has been in frontline IAF service with No. 45 Squadron since 2016 and has since equipped additional squadrons, participating in routine training and exercise activity. The improved Mk1A had not yet entered squadron service as of early 2026, with deliveries pending resolution of the F404-IN20 engine supply bottleneck and formal IAF handover expected from August-September 2026 onward.[7]
| Type | Single-Engine Multirole Fighter |
| Crew | 1 (2 in trainer variant) |
| Max speed | Mach 1.8 |
| Service ceiling | ~52,500 ft (16,000 m) |
| Operational radius | ~400-500 km |
| Engine | GE F404-IN20 turbofan |
| Radar | Uttam AESA (Mk1A) |
| Armament | 23 mm GSh-23 cannon; BVR/close-combat AAMs; precision-guided munitions |
| Manufacturer | Hindustan Aeronautics Ltd / ADA (India) |
| In service | 2016 (Mk1); Mk1A deliveries expected from Aug-Sep 2026 |
| Number ordered (India) | 180 (Mk1A: 83 + 97) |