posted on Jul, 11 2004 @ 01:19 AM
The twin-engined Medium Combat Aircraft (MCA) is a stealthy Gen-5 combat aicraft optimised for strike missions. It will complement LCA
and Su-30MKI as India's leading combat planes. If given the go-ahead, it should fly before 2010 and be inducted by 2015.
India is currently developing LCA a light multirole attack plane. The only components common between MCA and LCA will be part of the wing, the Kaveri
engine, and some systems and subsystems. MCA will be much heavier (12 ton dry weight).
The LCA has started flying in 2001 and should be inducted around 2008. MCA itself should make its first flight before 2010. It will face direct
competition from China's J-12 , which should come out before 2015.
Why India needs the MCA ?
MCA is basically envisioned as a replacement for the British Jaguar and Mirage 2000 the IAF flies, which will be phased out by 2015.
Propulsion
The State owned Gas Turbine Research Establishment [GTRE] was to indigenously develop the Kaveri engine to power the LCA and MCA. But there have been
major slippages in all the milestones. GE, SNECMA, and Klimov had all offered to provide the engines for this aircraft.
The Kaveri engines in the MCA will have a slightly higher dry thrust than in the LCA engine. These engines will also have thrust-vectoring nozzles. It
is unknown which company will be providing this technology, or whether it will be developed in India itself. A supercruise capability is not being
sought. The twin engined aircraft is planned to have a thrust ratio of 7:8:1. The MCA will use India's own radar-absorbent material to reduce radar
cross-section.
Kaveri :
Air-mass flow 78 kg/s
By-pass ratio 0.16
Overall pressure ratio 21.5
Turbine entry temperature 1487-1700 K
Maximum dry thrust 52 kN (5302 kg)
Maximum dry SFC 0.78 kg/hr/kg
After burner maximum power thrust 81 kN (8260 kg)
After burner maximum power SFC 2.03 kg/hr/kg
Thrust-to-weight ratio 7.8
Kaveri engine is a two-spool bypass turbofan engine having three stages of transonic low pressure compressor driven by a single-stage low pressure
turbine. The core engine consists of six-stage transonic compressor driven by single-stage cooled high pressure turbine. The engine is provided with a
compact annular combustor with airblast atomisers. The aerothermodynamic and mechanical designs of engine components have been evolved using many
in-house and commercially developed software for solid and fluid mechanics.
Kaveri three-stage transonic fan, designed for good stall margin and bird strike capability, handles an air mass flow of 78 kg/s and develops a
pressure Combustion Chamber Liner ratio of 3.4. The six-stage variable capacity transonic compressor of Kaveri develops a pressure ratio of 6.4. The
variable schedule of inlet guide vanes and two rows of stator is through FADEC control system to open the stator blades in a predetermined manner.
High intensity low UD ratio annular combustor of Kaveri engine incorporates air blast injection of fuel for uniform outlet temperature profile and
reduced carbon emission.
Kaveri high pressure turbine is provided with an efficient cooling design incorporating augmented convection-cum-film cooling for the vanes and
combination cooling for the rotor blade to handle up to 1700 K turbine entry temperature. Kabini engine comprising high pressure compressor, combustor
and high pressure turbine has undergone high altitude test at facilities abroad successfully demonstrating the flat rating concept of Kaveri engine
assembly and in particular the combustor high altitude ignition and stability performances.
Kaveri engine has been specifically designed for Indian environment. The engine is a variable cycle-flat-rated engine in which the thrust drop due to
high ambient, forward speed is well compensated by the increased turbine entry temperature at the spool Kabini altitude test speed. This concept has
been already demonstrated with high temperature and pressure condition in DRDO's High Mach Facility. Kaveri engine is controlled by Kaveri full
authority digital control unit [KADECU), which has been developed and successfully demonstrated at DRDO's test bed.
Stealth
Stealthiness will be a priority and hence the MCA will have two small, outward-canted fins and the external fuel tanks will be mounted above the
wings. Absence of a vertical fin improves stealth. However, not all weapons will be internal and hence will compromize the stealth.
If all progresses according to plan, MCA will become first military fighter that has no tail - at all. USA is the only country to have seriously
pursued such aircraft. It experimented with tail-less design in X-36. F-16X concept is another tail-less concept.
Tail-less design has been seen in Flying Wings, but these represent a separate class of aeroplanes. To realize the MCA, India will have to develop
cutting edge technology. US help in this area is obviously expected.