Search for Tejas engine nears its end: decision likely before March 2010, price will determine winner

Photo: One of the LCA prototypes at HAL Bangalore, fitted with fuel drop tanks

By Ajai Shukla

Bangalore

Business Standard, 24th Nov 09

For two years, the Aeronautical Development Agency --- the agency developing the Tejas Light Combat Aircraft (LCA) --- has searched for an engine to boost the performance of India’s homegrown fighter. With bids for two engines --- the General Electric F-414, and the Eurojet EJ200 --- submitted on 12th October, Business Standard has learned that ADA will select one before March 2010.

The GE F-404, one of fighter history’s iconic engines, currently powers the Tejas. But its 82-85 kilonewtons (KN) of thrust does not provide the acceleration or the sustained turning ability needed by the Tejas in air-to-air combat. ADA wants the Tejas to have 90-95 KN of thrust, which both the EJ200 and the GE F-414 provide. And so the F-404 will power only the first two Tejas squadrons; all subsequent LCAs, including the naval version, will fly with either the F-414 or the EJ200.

Dr Dipankar Banerjee, the DRDO’s Chief Controller of Aeronautics, says two crucial factors will determine the winner: which engine fits into the Tejas with minimal re-engineering; and which one works out cheaper (acquisition cost + operating cost).

The DRDO officer, who guides the Tejas programme, debunked the long-held belief that the Tejas would require major re-engineering for fitting the new engine. “We have evaluated both engines and we believe only minor changes will be needed in the fuselage of the Tejas”, said Dr Banerjee. “Which engine is selected will be largely determined by its cost.”

Both engines, however, need minor design modifications by their vendors to meet the specific requirements of the Tejas. According to Dr Banerjee, “The Eurofighter Typhoon is powered by two EJ200 engines, but the LCA has just a single engine. For safety reasons, it must have a re-ignition system to restart the engine automatically if it goes off in mid-flight.”

And since the selected engine will also power the naval Tejas, the EJ200 needs to be protected against the corrosive salt-water naval environment.

The EJ200’s rival, the GE F-414, has neither of these concerns; it already powers the single-engine Gripen fighter, as well as the F/A-18 Super Hornet, which the US Navy operates off aircraft carriers. But there are two other concerns over the F-414. Firstly, it needs to be tweaked to provide greater thrust during some periods of a flight, when it appears to deliver less power. And, since it is an American engine, export controls are potentially troublesome.

Eurojet, however, insists that re-ignite software is an integral part of the EJ200. Hartmut Tenter, Managing Director of Eurojet, explained to Business Standard, “If the EJ200 goes off in mid-flight, the aircraft decelerates sharply. The engine software recognizes that and automatically initiates the re-ignite procedure. It’s automatic; the pilot has to do nothing.”

Both Eurojet and General Electric consider this engine contract as vital. The order for 99 engines (plus options for another 49) is worth an estimated US $750 million. But, far more importantly, both see this contract as a way of getting a foot in the door for the US $11 billion Medium Fighter contract. Eurojet EJ200 engines power the Eurofighter Typhoon, while GE F-414s power both the F/A-18 and the Gripen NG. Getting a contract for the engine is seen as a giant first step towards getting a contract for the aircraft as well.

Fighter pilots say that a world-class engine makes a world-class fighter. Whenever two fighters face off in a dogfight, as pilots term an aerial duel, the one with the better engines almost always wins. In the old days, better engine power allowed a pilot to twist and turn sharply, to get behind the enemy, and then shoot him down with a burst of cannon fire.

Now, with missiles the primary air-to-air weapon, engine power is more important than ever. The enemy usually appears as a blip on the radar, which the pilot usually detects while “loitering” at low speeds to conserve fuel. He immediately guns his engine, accelerating hard towards the enemy, and launches his missile at nearly twice the speed of sound (Mach 2). As the missile screams towards the enemy fighter at around Mach 4, the pilot throws his fighter into a high-gravity U-turn to dodge the missile that his opponent would have launched by now. The pilot who can accelerate faster, launch first, and then turn away harder --- in other words, the pilot with the more powerful engine --- is usually the one who comes home alive.