HAL Tejas Mk2

In 2009, a Mark 2 was sanctioned as an improvement over Tejas Mark 1 while the current General Electric F404 engine employed by Tejas was to be replaced by a more powerful engine.

To meet the IAF's air staff qualitative requirements (ASQR), over time ADA had to make substantial changes to the basic Mk 1/Mk 1A air-frame to improve payload and performance.

Initially, it was planned to simply elongate the Tejas Mark 1 with a 0.5 m fuselage plug to accommodate more fuel, while fitting a more powerful engine with 65-100 kN of thrust.[8][9] But soon it was determined that this elongation of the air frame generated substantial amount of additional drag. Alongside that the IAF demanded at least 18 degrees per second sustained turn rate.[10]

To tackle that several years of design refinement followed to improve aerodynamic performance and payload. Development of MWF was envisioned only in 2014-15 period and configuration optimization studies commenced by ADA in November 2016.[11] Its whole platform was so drastically modified that the previous Mark 2 design concept, which was just a re-engined Mark1 air frame with fuselage plug, was discarded to transform the platform to be classified as a Medium-weight class aircraft. A final configuration was worked out in September 2018 and its basic design was frozen in December. At Bangalore in Aero India 2019, a latest version of the originally LCA Tejas Mark 2, now formally rechristened the Medium Weight Fighter, was unveiled for the first time.[12]

The aircraft entered detailed design phase after that during early months of 2020.[13] Metal-cutting is set to begin in February 2021, while long lead activities towards metal cutting (like, procurement of raw material) have already begun. The ‘roll out’ of first prototype of the MWF is scheduled for August 2022 with its first flight expected in September 2023. A total of four prototypes are being planned initially.[1]

While the original Tejas Mark 2 concept was merely an upgrade over the Tejas Mark 1, the MWF is a whole new aircraft developed based on it to complete the need of Indian airforce as MMRCA2.0 was scrapped earlier.

The most distinguishable external features of the new jet includes retractable air-to-air refueling probe against fixed one in Mark 1 FOC, close-coupled canards, increased number of weapon stations from 7 to 11. Other minor changes include a modified spine, air-intakes, canopy shape etc. and added hardpoints on wing-tips while its cannon is now mounted at the right wing-root.[14]

MWF is also to feature an indigenous integrated life support system-onboard oxygen generation system (ILSS-OBOGS) from Defence Bioengineering and Electromedical Laboratory (DEBEL), aircraft health and usage monitoring system (HUMS) to integrate various sensors onboard Tejas Mark 2 from Defence Institute of Advanced Technology (DIAT) and a built-in integrated electro-optic electronic warfare suite among other improvements to avionics.[15][16][17] It will have an infra-red search and track (IRST) system and a missile approach warning system (MAWS).[18] An increase in payload capacity to 6,500 kg (14,300 lb) and internal fuel capacity to over 3,400 kg (7,500 lb), will allow it to carry more weapons for longer range.[14]

For the power-plant, the General Electric F414 and Eurojet EJ200 were evaluated. In October 2010, GE F414 was selected as the lowest bidder.[19] The final deal for 99 aeroengines worth $822 million was signed by January 2013.[20] As per the agreement, eight engines were be bought off-the-shelf, while other 91 built in India under transfer-of-technology. [19]

In 2008, it was announced that an in-production powerplant would have to be selected; this was required to be in the 95 to 100 kilonewton (kN) (21,000–23,000 lbf) range to execute combat manoeuvres with optimal weapons load.[22][23] After evaluation and acceptance of technical offers for both the Eurojet EJ200 and the General Electric F414, the commercial quotes were compared in detail and GE's F414 was declared as the lowest bidder. The deal covered the purchase of 99 GE F414 engines, an initial batch will be supplied directly by GE and the remainder to be manufactured in India under a technology transfer arrangement.[24][25] According to the IAF, adopting the new powerplant required a three-to-four years of redesign work.

In October 2010, General Electric F414 was selected as engine for Tejas Mk 2.[26] The final contract for 99 aeroengines worth $822 million was signed in late 2012 or early 2013[27] with an option for 49 more that could be exercised later. As per the agreement, eight engines will be bought off-the-shelf, while other 91 will be built in India under transfer of technology.[28]

The F414-GE-INS6 has dry thrust of 12,994 lbf (58 kN) and 22,000 lbf (98 kN) of wet thrust.[29] F414-GE-INS6 features a Full Authority Digital Electronic Control (FADEC) system.[30]

MWF will have increased internal fuel capacity of 3.3 tonnes, while canards create some drag, the overall aerodynamic and fuel-capacity improvements ensures a range double than that of the Tejas.[1]

The aircraft will be equipped with a multi-sensor data fusion system which will feature an active electronically scanned array radar, infrared search and track and a missile approach warning system. It will also feature an internalized integrated electronic warfare suite. The aircraft will be designed to have network-centric warfare capacity.[31]

ADA is planning to integrate Uttam AESA radar on Tejas Mk 2 in collaboration with Electronics and Radar Development Establishment (LRDE).[32] Indian variant of Rafales are to sport Thales X-Guard fiber-optic towed decoy system and Traffic Collision Avoidance System (TCAS), which may be carried over to the MWF.[33]

MWF cockpit mockup at Defexpo 2020 Large Area Display.

Medium Weight Fighter's cockpit is to have a next-generation Wide Area Multifunction Display, and side-mounted control stick.[34]

The aircraft is planned to be equipped with an artificial intelligence based “optimally manned” cockpit. The cockpit will be designed such that the ground control would be able to takeover the controls of the aircraft in case the pilot becomes unconscious, after being alerted by a sensor in the helmet of the pilot.[35]