First Tejas Mark II engine to arrive in September

US refusing to cooperate on Advanced Medium Combat Aircraft engine, defence ministry floating global tender

By Ajai Shukla

Business Standard, 6th July 15

The plan to develop a more powerful, modernized version of the current Tejas fighter is getting a welcome boost. In September, US engine-maker General Electric (GE) plans to deliver the first F-414INS6 engine (hereafter F-414), which will power the Tejas Mark II.

The F-414 engine’s maximum power output of 98 kiloNewtons (kN) will make the Tejas Mark II faster and nimbler than the current Mark I fighter, which gets just 84 kN of peak power from its GE F-404IN engine. The F-414 will also provide the burst of power needed for the Naval Tejas to take off from an aircraft carrier deck on just 200 metres of runway.

In 2010, the Aeronautical Development Agency (ADA), which manages the Tejas programme, chose GE over Eurojet to supply 99 engines for the Tejas Mark II. Of these, 16 are being delivered fully-built, so that ADA can build prototypes of the Mark II fighter for ground and flight test programmes.

Meanwhile, Hindustan Aeronautics Ltd (HAL) will establish a facility to manufacture the remaining 83 engines in Bengaluru. With the Indian Air Force (IAF) and navy likely to order at least 160 Tejas Mark II fighters, the HAL facility could eventually build about 700 engines (assuming a fighter uses 3.5 engines in its service life).

For now, ADA is welcoming the arrival of the first F-414 engines. This will allow it to start building the first Mark II prototype, which it plans to fly within three years, i.e. by 2018-19. ADA says it will hand over the first production fighter to the IAF within six years, i.e. by 2021-22.

Presently, HAL Bengaluru is building the first 20 Tejas Mark I fighters, which were contracted in 2007. In 2010, the IAF committed itself to another 20 Mark I fighters, which will be contracted when the Tejas gets final operational clearance, probably by March 2016. These 40 fighters will use the F-404 engine.

Not everyone believes the Tejas Mark II, powered by the F-414, is a good idea. Aerospace experts like Pushpinder Singh of Vayu Magazine say the benefits of the more powerful F-414 would be negated by its additional weight and the re-design of the Tejas that they say will be needed to accommodate the engine.

Experts also argue the Tejas’ constricted air intake will prevent the F-414 from sucking in the air it requires, even with extensive redesign. In that case, the engine would not deliver its rated 98 kN thrust.

Rejecting this view, GE and ADA officials say they will accommodate the F-414 without problem or extensive redesign, and that it will perform to its designed potential.

Their claim is supported by the engine data on the GE website (see graphic below), which indicates the F-414 is no larger than the F-404. Nor is it significantly heavier, says ADA.

General Electric engines: comparison

	F-404-IN20	F-414-INS6	F-414 Enhanced Engine
Thrust	84 kN	98 kN	116 kN
Length	391 cm	391 cm	391 cm
Airflow	70 kg/sec	77.1 kg/sec	85 kg/sec
Max diameter	89 cm	89 cm	89 cm
Inlet diameter	71 cm	79 cm	79 cm
Pressure ratio	28:1	30:1	30:1

(Source: General Electric official website)

While GE has bagged the deal to supply India the F-414, an even bigger prize could prove elusive --- the supply of a more powerful version of the F-414 for the Advanced Medium Combat Aircraft (AMCA), a fifth-generation medium fighter that ADA plans to develop, with the IAF standing ready to buy 200.

As this blog reported (June 1, “Carter to face Indian demand for engine technology”) the defence ministry has asked the United States to let the Defence R&D Organisation (DRDO) work with GE in jointly upgrading the F-414 to a rating of 110 KN of peak power. ADA believes the AMCA needs 220 kN of peak power from its twin engines.

This is welcomed by GE, which had earlier worked for the US Navy on upgrading the F-414 to a 116 kN engine designated F-414 Enhanced Engine. With that project now shelved, GE would like to see it revived with Indian partnership, funding and a large assured market.

Yet, Washington is stonewalling the Indian request, even though the two countries had established a “joint working group” to explore cooperation in engine design during President Obama’s visit to India in January.

A disappointed Indian defence ministry is now issuing a global tender, inviting aero engine firms to co-develop a suitable engine with the DRDO.

Senior defence ministry sources say that Eurojet, the European consortium whose EJ200 engine lost out to GE’s F-414 in the contest to power the Tejas Mark II, has satisfied the DRDO it can uprate the EJ200 to 110 kN.

Snecma, the French company that builds the Rafale’s M-88 engine, will also be issued a tender. However the M-88, which currently generates 75 kN of thrust, cannot be uprated beyond 105 kN.

“Fighters are designed around a pre-selected engine. We will issue the tender quickly and select an engine for the AMCA so that the programme does not get delayed. If Washington chooses to deny India engine technology by preventing GE from working with the DRDO, that will have its own implications”, says a top defence ministry official.