Supersonic fighter is on its way

India’s fighter strength has been declining in the recent years, as the MiG-21s that comprises the bulk of its fleet are lost in crashes, or retired due to age and wear. While the buzz might be around the multi-billion dollar medium multi-role combat aircraft (MMRCA) deal for the purchase of 126 fighter planes for which American, Russian, French, Swedish and European fighter makers are hot in the race, but that still leaves replacement of the MiG-21 fleet.

In such a scenario, the news that Tejas, India’s second indigenous jet fighter design, after the HF-24 Marut of the 1950s, successfully undertook its maiden test flight this month, has brought cheers to the country’s defence establishment. With this successful flight, the indigenous light combat aircraft (LCA) programme is close to the initial operations clearance, which is expected to be completed by December this year, according to Defence Research Development Organisation (DRDO). The remaining effort will mostly revolve around flight testing and demonstration of sensors and weapon performance. In a nutshell: After long delays, Tejas is scheduled for induction into Indian Air Force (IAF) service in December, 2010.

Tejas is being built by Hindustan Aeronautics Ltd (HAL) for the Indian Air Force (IAF) and the Indian Navy. The LCA was designed by Aeronautical Development Agency (ADA) in Bangalore. The IAF has a requirement of 140 single-seat fighters and 20 two-seat LCA trainers for squadron service in the next 10 years. It has ordered 20 LCAs, which are scheduled to be delivered by 2013. Development is underway for the naval version of the LCA, which can be operated from an aircraft carrier. Two naval prototypes will be manufactured and flown to obtain clearance for deck operations.

Tracing its history, the LCA project was sanctioned in 1982 with a budget of Rs 560 crore to develop a F-16 class fighter aircraft to replace MiG-21 fighters in the IAF. Analysts inform that close to Rs 6,000 crore has been spent in the country’s efforts to upgrade its national defence capabilities through home-made production of fighter planes.

Tejas is claimed to be the world’s smallest, light weight, multi-role combat aircraft designed to meet the requirements of Indian Air Force as its frontline multi-mission single-seat tactical aircraft to replace the MiG-21 series of aircraft. The

Tejas design has been configured to match the demands of modern combat scenario such as speed, acceleration, maneuverability and agility. The LCA integrates modern design concepts like static instability, digital fly-by-wire flight control system, integrated avionics, glass cockpit, primary composite structure, multi-mode radar, microprocessor based utility and brake management systems.

Senior scientists from Aeronautical Development Agency (ADA), National Aerospace Laboratories (NAL) and Aeronautical Development Establishment (ADE) have been involved in the development and flight test planning of the newly integrated flight control software which was used by the test aircraft.

According to PS Subramanyam, programme director, ADA, the Tejas team is now heading to central India to carry out hot weather trials.

Designed as a single-engine tactical fighter, Tejas has a compound delta-wing platform to achieve weight reductions. The wing design, combined with a blended-wing body, delivers high performance. The design allows the aircraft to be integrated with guided air-to-surface and anti-ship weapons for multi-role and multi-mission capabilities. The fuselage is a thin walled and integrally stiffened structure, designed to sustain internal pressure without stiffener debonding. It features complex shapes and contours using integral structures in large scale.

The glass cockpit is equipped with a head-up display (HUD) and two multifunction displays (MFDs) that provide the required information to the pilot.

The HUD displays critical information required in close combat situations. The modern avionics systems and an effective pilot-vehicle interface are installed in the cockpit. The hands on throttle and stick (HOTAS) concept ensures the availability of all flight controls during adverse conditions.

Among others, Tejas features an integrated digital avionics suite, configured around the MIL-STD-1553B bus system. The 32-bit mission computer (MC) can perform mission-oriented computations, flight management, reconfiguration/redundancy management and in-flight system self tests.

On the weapons side, Tejas is claimed to be a precision weapon launch platform with seven hardpoints to carry a range of air-to-air missiles, anti-ship missiles, unguided rockets and conventional/retarded bombs. The air-to-air missiles include Astra BVRAAM, Vympel R-77 and R-73. The air-to-surface missiles are Kh-59ME TV guided stand-off missile and Kh-59MK laser-guided stand-off missile.

A 23mm twin-barrel GSh-23 cannon is also mounted on the fighter aircraft.

The advanced multimode radar (MMR) track-while-scan feature allows the tracking and engaging of multiple targets simultaneously. It also provides ground mapping and look-down shoot-down capabilities. The sensor suite provides threat detection, and a low visual signature that helps the aircraft to perform better in close air combat environments. The LCA can also be fitted with additional sensors for guidance, navigation and reconnaissance purposes.

Most importantly, Tejas is powered by a General Electric F404-GE-IN20 turbofan engine. The engine is rated to supply 53.9kN dry thrust and 85kN thrust with afterburn. Fuel tanks are integrated into the fuselage and wings, and auxiliary fuel tanks of 800lt and 1,200lt can be fitted under fuselage to extend the range. An in-flight refuelling probe is also fitted to the starboard side to further extend Tejas’s range and endurance.

India’s efforts to become self-reliant by taking up home production of Tejas aircraft were marred by hitches in the development phase. Through the use of modern design techniques, the indigenous effort might take to the skies soon.