Indian Air force clears Tejas Mark 2 design, production in 2023

With the Indian Air Force (IAF) placing orders for 123 Tejas fighters and the Royal Malaysian Air Force (RMAF) also evaluating the nippy light fighter, the country’s home-grown light combat aircraft (LCA) is evolving from its current, single-engine, Mark 1 avatar to a more sophisticated, twin-engine, fifth-generation fighter that can dominate the South Asian skies.

A major landmark in that evolution was passed on November 15, when the Deputy Chief of Air Staff (DCAS), Air Marshal Narmdeshwar Tiwari, accepted the comprehensive design review (CDR) of the LCA Mark 2.

A CDR is a multi-discipline, technical review that is a critical step in designing an aircraft. It involves examining the air frame design to ascertain that the aircraft is ready for fabrication and testing and it would achieve its stipulated performance within cost, schedule and risk.

The Indian Air Force’s (IAF’s) acceptance of the CDR clears the way for Hindustan Aeronautics Ltd (HAL) to start releasing drawings for fabricating the Mark 2’s first prototype.

Alongside building the Mark 2 prototype, HAL and the Aeronautical Development Agency (ADA) — the Defence Research and Development Organisation (DRDO) agency that oversees the entire Tejas programme — must still resolve a few glitches that remain in the Mark 1 fighter; and also complete delivery of the IAF’s order of 40 Mark 1 (two squadrons) and 83 Mark 1A (four squadrons).

During an exclusive visit to HAL’s Tejas production line in Bengaluru, Business Standard was briefed in detail on the status of the indigenous fighter project. This includes the evolution of the Mark 1 and 1A into the Mark 2; simultaneous development of the navy’s eponymous Twin-Engine Deck Based Fighter (TEDBF) for its aircraft carriers; design and development of the fifth-generation Advanced Medium Combat Aircraft (AMCA), and the development of the Combat Air Teaming System (CATS), a futuristic combination of manned-unmanned aircraft that is the future of air warfare.

The first two Mark 1 squadrons are already operational in Sulur, near Coimbatore. Each of them is authorised 20 fighters, including four twin-seat trainers. The trainers’ specifications were finalised late, so they will be built along with the 16 trainers of the four Mark 1A squadrons.

The IAF has cleared the “final operational certification” (FOC) for the Mark I fighter, even though that involved granting 25 concessions — or performance shortfalls from the IAF’s specified requirements. HAL, ADA and the IAF are working together to resolve these shortfalls.

Twelve issues have already been resolved, the most important one being: Equipping the Tejas to re-fuel in-flight, by day or night. In recent trials at Gwalior, the Tejas proved it could refuel into internal fuel tanks or external drop tanks, from IL-78 refuellers or from Sukhoi-30MKI acting as “buddy refuellers.” This capability is operationally vital, since it effectively increases the range of the Tejas.

Another shortfall that has been resolved is the capability to monitor fuel levels in the Tejas through an integrated Environmental Control and Fuel Management (ECFM) system. This tells the pilot, via a smart multi-function display in the Tejas’ glass cockpit, the fuel level in each of the tanks.

Also being proved is the firing of the Tejas Mark 1’s Gasha 23 mm gun. The gun had been integrated onto the fighter, but live firing was pending. Now butt firing trials and air-to-air firing is being carried out in Nashik.  

Waiting to be integrated onto the Tejas is the indigenous Astra air-to-air missile and Safran’s Highly Agile Modular Munition Extended Range (HAMMER) air-to-ground bomb. Towards this, HAL does the mechanical and electrical integration, while the DRDO handles the software and the weapons algorithm.

The 13 shortfalls that still remain include fatigue tests to establish the fighter’s service life span.

These tests involve taking an aircraft from the production line and subjecting it to repetitive loading. All combat aircraft are initially released with a designated service life — 500 hours in the case of the LCA. As more and more hours are logged and the data accumulates, the manufacturer increases the designated lifespan proportionately. It takes about nine years of fatigue testing to establish 3,000 hours of service life of the aircraft.

While these capabilities are being tested on the Tejas Mark 1, the Mark 1A is being fitted with an active electronically scanned array (AESA) radar, an electronic warfare (EW) suite that includes a jammer, the Combined Interrogator and Transponder (CIT) — an IFF plus system — and a digital map generator.

The digital map generator, designed by HAL’s MCSR&DC (Mission and Combat Systems R&D Centre), carries the complete map data of the country and neighbouring areas. Depending upon the Tejas’ mission, it extracts the digitised map of the current mission area and transfers it to the pilots’ display, where he can easily access it.

HAL is also integrating the Advanced Short Range Air-to-Air Missile (ASRAAM) onto the Mark 1A. The ASRAAM, which has a range of 60-70 kilometres, was bought by the IAF from MBDA UK, for upgrading its Jaguar fighters. Now each Tejas too will carry two of these missiles on its outboard stations.

Another modification involves reshaping the cockpit floor to enable bigger pilots — with shoe size up to 10, which includes 95 per cent of all IAF pilots — to fit into the cockpit and fly the aircraft comfortably.

“The IAF has allotted HAL a Tejas Mark 1, numbered SP-25 (series production aircraft number 25), for integrating these modifications. We are almost through and will start flight testing in December. It will take about two years to complete flight testing, i.e., by end-2023,” said HAL chairman, R Madhavan.

Meanwhile, flight-testing continues. The first Mark 1A is to be delivered in February 2024 with all modifications installed. 

Since the last Tejas Mark 1 is being completed in the same time frame, the jigs, fixtures and assembly line used to build the Tejas Mark 1 will be diverted to building the Mark 1A.