45 Squadron IAF - Flying Daggers, based at Sulur Air Force Station (AFS) in the southern Indian state of Tamil Nadu, was the first to have their MiG-21 Bisons replaced with the Tejas.

HAL's Hyderabad division and the DRDO's Electronics and Radar Development Establishment (LRDE) laboratory were selected to jointly lead the MMR programme, and work commenced in 1997.

The successful endeavours were mastery in the FBW flight control system,[39][28] the development and manufacturing of carbon-fibre composite structures and skins, and a modern glass cockpit.

[42][43] On 20 December 2021, Ministry of Defence (MoD) in a written reply during winter session of Rajya Sabha clarified that the HAL Tejas is no longer considered as a replacement for the Mikoyan-Gurevich MiG-21, instead it is now part of a general IAF fleet modernisation programme.

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.

[56] On 15 April 2023, HAL received a flight clearance certificate for the Aircraft Mounted Accessory Gear Box (AMAGB) bearings and power take-off shaft.

[73] 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.

[82] In order to produce the BMI Engine Bay Door for the Tejas Mark 1A, HAL and National Aerospace Laboratories inked a technology transfer agreement.

[83] 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.

[96][65] 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.

[112] 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.

[120] 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.

[124] 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[37] and so on, reduces the overall radar cross-section of the aircraft.

[133][134] It has an electronic warfare (EW) suite domestically developed by Defence Avionics Research Establishment (DARE), which consists of a radar warning receiver (RWR), integrated self-protection jammer,[135] chaff and flare dispenser system.

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.

[122][37] 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.

[152] 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.

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.

[185][186] However, as of March 2024, the IAF's latest requests for software upgrades and minor design changes caused the delay in delivery timeline, as per to sources within the military and defence establishment.

[196] Again in September, it was reported that the Tejas Mk1A will be delivered from October 2024, as the fighter aircraft's Israeli software integration being finished and is undergoing final trials.

[198][199][200] As of late December, reports suggest that further critical trials of Tejas Mk1A using Category B F404 engines is to commence in January 2025 as a part of a contingency plan.

The trials will also include Astra Mk1 air-to-air beyond visual range missiles, EL/M-2052 and indigenous Electronic Warfare Suite (radar warning receiver and advanced self-protection jammer).

45 Squadron – Group Captain Samrath Dhankhar, DASH IV HMDS enables the Tejas pilot to take full advantage of high off-boresight close combat missiles,[210] such as Python-5 and R-73.

[241] Subsequently, there were indications that the Argentines were willing to look at the JF-17 because of concerns that the time and money required to modify the Tejas to remove non-British parts was beyond what Buenos Aires was willing to spend.

"[244][245] In July 2023,[246] Argentine newspaper La Nacion reported that Tejas had been eliminated, with the remaining options being second-hand Danish F-16 fighters or Chinese-Pakistani JF-17s, both which the bidding selection board deemed more advantageous.

[253] In February 2022, the Australian government decided to take up a proposal by BAE to upgrade and refurbish its Hawks with new engines and avionics, extending their lifespan until 2032.

[254] The Botswana Defence Force Air Wing had approached HAL to procure the Tejas for potentially replacing its Canadair CF-5s due to the aircraft's age and problems of acquiring needed parts for maintenance.

[280] The FA-50 was reportedly chosen because of it being a tried-and-tested platform in service with numerous countries while the Tejas is largely unproven and untested, with the Indian Air Force being the sole operator.

[286] In February 2024, HAL reported that it has offered the Tejas Mark 1A to the PADC as a naval strike platform, equipped with the BrahMos NG missile.