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Light Combat
Aircraft (LCA)
Country of Origin: India
Type: Multirole
Single Seat fighter
Description: |
LCA on its maiden flight over Banglore |
The Indian Light
Combat Aircraft (LCA) is 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 delta wing configuration , with no
tailplanes or foreplanes, features a single vertical fin. The LCA is
constructed of aluminium-lithium alloys, carbon-fibre composites, and
titanium. LCA integrates modern design concepts and the state-of-art
technologies such as relaxed static stability, flyby-wire Flight Control
System, Advanced Digital Cockpit, Multi-Mode Radar, Integrated Digital
Avionics System, Advanced Composite Material Structures and a Flat Rated
Engine.
The LCA design has been configured to match the demands of modern combat
scenario such as speed, acceleration, maneuverability and agility. Short
takeoff and landing, excellent flight performance, safety, reliability
and maintainability, are salient features of LCA design. 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.
The avionics system enhances the role of Light Combat Aircraft as an
effective weapon platform. The glass cockpit and hands on throttle and
stick (HOTAS) controls reduce pilot workload. Accurate navigation and
weapon aiming information on the head up display helps the pilot achieve
his mission effectively. The multifunction displays provide information
on engine, hydraulics, electrical, flight control and environmental
control system on a need-to-know basis along with basic flight and
tactical information. Dual redundant display processors (DP) generate
computer-generated imagery on these displays. The pilot interacts with
the complex avionics systems through a simple multifunction keyboard,
and function and sensor selection panels. A state-of-the-art multi-mode
radar (MMR), laser designator pod (LDP), forward looking infra-red (FLIR)
and other opto-electronic sensors provide accurate target information to
enhance kill probabilities. A ring laser gyro (RLG)-based inertial
navigation system (INS), provides accurate navigation guidance to the
pilot. An advanced electronic warfare (EW) suite enhances the aircraft
survivability during deep penetration and combat. Secure and
jam-resistant communication systems, such as IFF, VHF/UHF and
air-to-air/air-to-ground data link are provided as a part of the
avionics suite. All these systems are integrated on three 1553B buses by
a centralised 32-bit mission computer (MC) with high throughput which
performs weapon computations and flight management, and
reconfiguration/redundancy management. Reversionary mission functions
are provided by a control and coding unit (CCU). Most of these
subsystems have been developed indigenously.
The digital FBW system of the LCA is built around a quadruplex
redundant architecture to give it a fail op-fail op-fail safe
capability. It employs a powerful digital flight control computer (DFCC)
comprising four computing channels, each powered by an independent power
supply and all housed in a single line replaceable unit (LRU). The
system is designed to meet a probability of loss of control of better
than 1x10-7 per flight hour. The DFCC channels are built around 32-bit
microprocessors and use a safe subset of Ada language for the
implementation of software. The DFCC receives signals from quad rate,
acceleration sensors, pilot control stick, rudder pedal, triplex air
data system, dual air flow angle sensors, etc. The DFCC channels excite
and control the elevon, rudder and leading edge slat hydraulic
actuators. The computer interfaces with pilot display elements like
multifunction displays through MIL-STD-1553B avionics bus and RS 422
serial link.
Multi-mode radar (MMR), the primary mission sensor of the LCA in its
air defence role, will be a key determinant of the operational
effectiveness of the fighter. This is an X-band, pulse Doppler radar
with air-to-air, air-to-ground and air-to-sea modes. Its
track-while-scan capability caters to radar functions under multiple
target environment. The antenna is a light weight (<5 kg), low
profile slotted waveguide array with a multilayer feed network for broad
band operation. The salient technical features are: two plane monopulse
signals, low side lobe levels and integrated IFF, and GUARD and BITE
channels. The heart of MMR is the signal processor, which is built
around VLSI-ASICs and i960 processors to meet the functional needs of
MMR in different modes of its operation. Its role is to process the
radar receiver output, detect and locate targets, create ground map, and
provide contour map when selected. Post-detection processor resolves
range and Doppler ambiguities and forms plots for subsequent data
processor. The special feature of signal processor is its real-time
configurability to adapt to requirements depending on selected mode of
operation.
Seven weapon stations provided on LCA offer flexibility in the choice of
weapons LCA can carry in various mission roles. Provision of drop tanks
and inflight refueling probe ensure extended range and flight endurance
of demanding missions. Provisions for the growth of hardware and
software in the avionics and flight control system, available in LCA,
ensure to maintain its effectiveness and advantages as a frontline
fighter throughout its service life. For maintenance the aircraft has
more than five hundred Line Replaceable Units (LRSs), each tested for
performance and capability to meet the severe operational conditions to
be encountered.
Hindustan Aeronautics Limited (HAL) is the Principal Partner in the
design and fabrication of LCA and its integration leading to flight
testing. The LCA has been designed and developed by a consortium of five
aircraft research, design, production and product support organizations
pooled by the Bangalore-based Aeronautical Development Agency (ADA),
under Department of Defense Research and Development Organization (DRDO).
Various international aircraft and system manufacturers are also
participating in the program with supply of specific equipment, design
consultancy and support. For example, GE Aircraft Engines provides the
propulsion.
The first prototype of LCA rolled out on 17 November 1995. Two aircraft
technology demonstrators are powered by single GE F404/F2J3 augmented
turbofan engines. Regular flights with the state-of-the-art "Kaveri"
engine, being developed by the Gas Turbine Research Establishment (GTRE)
in Bangalore, are planned by 2002, although by mid-1999 the Kaveri
engine had yet to achieve the required thrust-to-weight ratio.
The LCA is India's second attempt at an indigenous jet fighter design,
following the somewhat unsatisfactory HF-24 Marut Ground Attack Fighter
built in limited numbers by Hindustan Aeronautics Limited in the 1950s.
Conceived in 1983, the LCA will serve as the Indian air force's
frontline tactical plane through the year 2020. The LCA will go into
service in the 2003-2005 timeframe.
Following India's nuclear weapons tests in early 1998, the United
States placed an embargo on the sale of General Electric 404 jet engines
which are to power the LCA. The US also denied the fly-by-wire system
for the aircraft sold by the US firm Lockheed-Martin. As of June 1998
the first flight of the LCA had been delayed due to systems integration
tests. The first flight awaits completion of the Digital Flight Control
Systems, being developed by the Aeronautical Development Establishment (ADE).
Source: www.FAS.org (Federation of
American Scientists) |
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