Bangalore: The indigenously built Tejas Light Combat Aircraft (LCA), which received its Initial Operational Clearance (IOC) today, could also be exported to friendly countries, defence officials said.

''We would also consider selling the planes to other friendly countries, but that would be decided only after the induction of the fighter into the IAF,'' sources said.

Tejas is the smallest lightweight, multi-role, single-engine tactical fighter aircraft in the world. It is being developed as a single-seat fighter aircraft for the Indian Air Force and also as a two-seat training aircraft.

Initials reports had suggested that the Indian Air Force may order as many as 200 of these fighters.

The testing of a carrier-borne version of the Tejas, in single-seat and two-seat versions with a modified nose, strengthened landing gear and an arrestor-hook, is also afoot. The carrier variant has retractable canards and adjustable vortex control.

Indian defence sources point with pride to many of the technologies developed indigenously for the fighter.

The On Board Oxygen Generating System (OBOGS), is one of the highlights of the LCA. Since carrying oxygen adds to the weight of the aircraft, this technology ensures that oxygen generated inside for the pilot. Such technology, it is pointed out is available with only three other countries.

Besides, the fighter features fly-by-wire systems, and other state-of-the-art digital technologies.

The fully developed version of the LCA would be the Mark II, which would eventually lead to the development of the more advanced fighter platforms like the stealth, fifth generation Medium Combat Aircraft (MCA) among others.

The development of technologies for the LCA has allowed development of Unmanned Aerial Combat Vehicle (UCAVs) as well.

LCA Technologies

The Indian government's "self-reliance" dictum for the LCA included indigenous development of the three of the most sophisticated systems in existence today - the fly-by-wire (FBW) flight control system (FCS), multi-mode pulse-doppler radar and an afterburning turbofan engine.

The ambitiousness of the LCA programme in terms of pursuing self-reliance objectives can be gauged from the fact that out of a total of 35 major avionics components and line-replaceable units (LRUs), only three involve foreign systems. However, even among these three, when the LCA reaches the production stage, one or two may be supplied by Indian companies.

A few other important items of equipment (such as the Martin-Baker ejection seat) have been imported. But the Martin-Baker ejection seat is virtually a universal standard and virtually there are no aircraft systems around the world that manage without their technology.

Many systems planned to be imported had to be developed in-house thanks to a sanctions regime imposed by the United States of America after the May 1998 nuclear weapons trials.

Of the five critical technologies the ADA identified at the beginning of the LCA programme as required to be mastered in order to design and build a "completely indigenous" fighter, two have been entirely successful: the development and manufacture of advanced carbon-fibre composite (CFC) structures and skins and a modern "glass cockpit."

In fact, ADA has had a profitable commercial spin-off in its Autolay integrated automated software system for the design and development of 3-D laminated composite elements (which has been licensed to both Airbus and Infosys).

With significant advances being achieved by India's domestic industries, it is estimated that more than 70% of the components in the LCA are manufactured in India and the dependence on imported components used would progressively reduce in the coming years.

The automatic flight control system (AFCS) of the Tejas has been highly praised by all of its test pilots, one of whom said that he found it easier to take off with the LCA than in a Mirage 2000.

The LCA is constructed of aluminium-lithium alloys, carbon-fibre composites (C-FC), and titanium-alloy steels. The Tejas employs C-FC materials for up to 45% of its airframe by weight, including in the fuselage, wings, elevons, tailfin, rudder, air brakes and landing gear doors.

Composites are used to make an aircraft both lighter and stronger at the same time compared to an all-metal design, and the LCA's percentage employment of C-FCs is one of the highest among contemporary aircraft of its class.

Apart from making the plane much lighter, there are also fewer joints or rivets, which increases the aircraft's reliability and lowers its susceptibility to structural fatigue cracks.

The Tejas has a night vision goggles (NVG)-compatible "glass cockpit" that is dominated by an indigenous head-up display (HUD), three 5 in x 5 in multi-function displays, two Smart Standby Display Units (SSDU), and a "get-you-home" panel which provide the pilot with essential flight information in case of an emergency.

The glass cockpit features reduce pilot workload and increase situation awareness by allowing the pilot to access navigation and weapon-aiming information with minimal need to spend time "head down" in the cockpit.

The coherent pulse-Doppler Multi-Mode Radar (MMR) in development is designed to keep track of a maximum of 10 targets and allowing simultaneous multiple-target engagement. The MMR system is being designed to perform multi-target search, track-while-scan (TWS), and ground-mapping functions.

It features look-up/look-down modes, low-/medium-/high-pulse repetition frequencies (PRF), platform motion compensation, doppler beam-sharpening, moving target indication (MTI), Doppler filtering, constant false-alarm rate (CFAR) detection, range-Doppler ambiguity resolution, scan conversion, and online diagnostics to identify faulty processor modules.

The electronic warfare (EW) suite is designed to enhance the Tejas' survivability during deep penetration and combat. This EW suite, known as "Mayavi", includes a radar warning receiver (RWR), self-protection jammer, laser warning system, missile approach warning system, and chaff/flare dispenser.

A great degree of 'stealth' features have been integrated into the Tejas design.  Being very small, there is an inherent degree of "visual stealth", but the airframe's use of a high degree of composites (which do not reflect radar waves), a Y-duct inlet which shields the engine compressor face from probing radar waves, and the application of radar-absorbent material (RAM) coatings are intended to minimise its susceptibility to detection and tracking by the radars of enemy fighters, airborne early warning and control (AEW&C) aircraft, active-radar air-to-air missiles (AAM), and surface-to-air missile (SAM) defence systems.

The Tejas has a mounted 23mm twin-barrel GSh-23 cannon with 220 rounds of ammunition.

It has a total of eight hard points and can carry external fuel drop tanks.

The Tejas is capable of carrying the Israeli Python 5 and Derby, as also the Russian R-73 and the Indian Astra beyond visual range air-to-air missiles. Other missiles that can be carried are the Russian Vympel R-77 AAM.

It can carry the Kh-59ME TV-guided stand-off missile as also the Kh-59MK laser-guided stand-off Missile.

For the naval version it can carry the Kh-35 and Kh-31 anti-ship missiles.

It is also equipped with the advanced LITENING targeting pod.