HAL Tejas
Encyclopedia
The HAL Tejas (Sanskrit: तेजस् "Radiant", t̪eːdʒəs) is a lightweight multirole fighter
developed by India. It is a tailless, compound delta-wing design powered by a single engine. It came from the Light Combat Aircraft (LCA) programme, which began in the 1980s to replace India's ageing MiG-21
fighters. Later the LCA was officially named "Tejas" by then Prime Minister
Atal Bihari Vajpayee
.
The Tejas has the delta wing configuration, with no tailplanes or foreplanes, and features a single vertical fin. It integrates technologies such as relaxed static stability
, fly-by-wire flight control system
, advanced digital cockpit, multi-mode radar, integrated digital avionics system, advanced composite material structures and a flat rated
engine. The IAF is reported to have a requirement for 200 single-seat and 20 two-seat conversion trainers, while the Indian Navy may order up to 40 single-seaters to replace its Sea Harrier FRS.51
and Harrier T.60.
The Tejas achieved a speed of over 1350 kilometres per hour (838.9 mph) per hour during its sea level flight trials, thus becoming the second supersonic fighter manufactured indigenously by Hindustan Aeronautics Limited after the HAL Marut. The Tejas was cleared in January 2011 for use by Indian Air Force pilots. It will not reach final operational clearance until 2014.
(HAL) should design and develop an advanced technology fighter aircraft around a proven engine. Based on a 'Tactical Air Support Aircraft' ASR markedly similar to that for the Marut, HAL completed design studies in 1975, but the project fell through due to inability to procure the selected "proven engine" from a foreign manufacturer and the IAF's requirement for an air superiority fighter with secondary air support and interdiction capability remained unfulfilled.
In 1983 IAF realized the need of an indigenous combat aircraft for two primary purposes. The principal and most obvious goal was the development of a replacement aircraft for India's ageing MiG-21 fighters. The MiG-21 has been the mainstay of the Indian Air Force
since the 1970s. The "Long Term Re-Equipment Plan 1981" noted that the MiG-21s would be approaching the end of their service lives by the mid-1990s, and that by 1995 the IAF would lack 40% of the aircraft needed to fill its projected force structure requirements.
The LCA programme's other main objective was to serve as the vehicle for an across-the-board advancement of India's domestic aerospace
industry. The value of the aerospace "self-reliance" initiative is not simply the production of an aircraft, but also the building of a local industry
capable of creating state-of-the-art
products with commercial spin-offs for a global market. The LCA program was intended in part to further expand and advance India's indigenous aerospace capabilities.
To better accomplish these goals, the government chose to take a different management approach, and in 1984 established the Aeronautical Development Agency
(ADA) to manage the LCA programme.Although the Tejas is most often described as a product of Hindustan Aeronautics Limited
(HAL), responsibility for the development of the Tejas actually belongs to ADA, a national consortium of over 100 defence laboratories, industrial organisations, and academic institutions with HAL being the principal contractor.
The Indian government's "self-reliance" goals for the LCA include indigenous development of the three most sophisticated — and hence most challenging — systems: the fly-by-wire (FBW) flight control system
(FCS), multi-mode pulse-doppler radar
, and afterburning turbofan engine
. Although India has had a policy of strictly limiting foreign participation in the LCA programme, these are the only major LCA systems on which the ADA has had to invite significant foreign technological assistance and consultancy. Moreover, the engine and radar are also the only major systems for which the ADA has seriously considered substituting foreign equipment.
The ambitiousness of the LCA programme in terms of pursuing self-reliance in aviation technologies is illustrated by the fact that out of a total of 35 major avionics
components and line-replaceable unit
s (LRUs), only three involve foreign systems. These are the multi-function display
s (MFDs) by Sextant (France) and Elbit
(Israel), the helmet-mounted display and sight (HMDS) cueing system by Elbit, and the laser pod supplied by Rafael
(Israel). However, even among these three, when the LCA reaches the production stage, the MFDs are expected to be supplied by Indian companies. A few other important items of equipment (such as the Martin-Baker ejection seat) have been imported. As a consequence of the embargo imposed on India after its nuclear weapons tests
in May 1998, many items originally planned to be imported were instead developed indigenously .
Of the five critical technologies the ADA identified at the beginning of the LCA programme as needing to be mastered for India to be able 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
). These successes have gone mostly unnoticed in the shadow of the problems encountered with the other three key technology initiatives. Nonetheless, as a result of the accomplishments of India's domestic industries, presently about 70% of the components in LCA are manufactured in India and the dependence on imported components used would be progressively reduced in the coming years.
HAL serves as the prime contractor and has leading responsibility for LCA design, systems integration, airframe manufacturing, aircraft final assembly, flight testing, and service support. The ADA itself has primary responsibility for the design and development of the LCA's avionics suite and its integration with the flight controls, environmental controls, aircraft utilities systems management, stores management system, etc.
Of particular importance are the initiatives to develop an indigenous flight control system, radar, and engine for the LCA. The National Aeronautics Laboratory (NAL)—now called the National Aerospace Laboratories
—was selected to lead the development of the flight control laws, supported by the Aeronautical Development Establishment
(ADE). HAL and the Electronics and Radar Development Establishment (LRDE) are jointly developing the Tejas Multi-Mode Radar (MMR). The GTRE is responsible for the design and parallel development of the GTX-35VS Kaveri
afterburning turbofan engine for the Tejas.
The IAF's Air Staff Requirement for the LCA were not finalised until October 1985. This delay rendered moot the original schedule which called for first flight in April 1990 and service entry in 1995; however, it also proved a boon as it is gave the ADA time to better marshal national R&D and industrial resources, recruit personnel, create infrastructure, and to gain a clearer perspective of which advanced technologies could be developed indigenously and which would need to be imported.
Project definition commenced in October 1987 and was completed in September 1988. Dassault Aviation
of France was hired as a consultant to review the PD and provide advice based on its extensive aviation expertise. The PD phase is a critical early element in the aircraft design and development process because from this flow key elements of the detailed design, manufacturing approach, and maintenance requirements.
ed machine with relaxed static stability (RSS) to enhance maneuverability performance. The sophisticated avionics and advanced composite structure specified caused some concern almost immediately, and the IAF expressed doubt that India possessed sufficient technological infrastructure to support such an ambitious project. A governmental review committee was formed in May 1989 which reported out a general view that Indian infrastructure, facilities and technology had advanced sufficiently in most areas to undertake the project. As a measure of prudence, though, it was decided that the full-scale engineering development (FSED) stage of the programme would proceed in two stages.
Phase 1 would focus on "proof of concept
" and would comprise the design, development and testing (DDT) of two technology demonstrator aircraft (TD-1 and TD-2) and fabrication of a structural test specimen (STS) airframe; only after successful testing of the TD aircraft would the Indian government give its full support to the LCA design. This would be followed by the production of two prototype
vehicles (PV-1 and PV-2), and creation of the necessary basic infrastructure and test facilities for the aircraft would begin.
Phase 2 would consist of the manufacturing of three more prototype vehicles (PV-3 as the production variant, PV-4 as the naval variant, and PV-5 as the trainer variant) and a fatigue test specimen, and the construction of further development and test facilities at various work centres.
Phase 1 commenced in 1990 and HAL started work on the technology demonstrators in mid-1991; however, a financial crunch resulted in full-scale funding not being authorized until April 1993, with significant work on FSED Phase 1 commencing in June. The first technology demonstrator, TD-1, was rolled out on 17 November 1995 and was followed by TD-2 in 1998, but they were kept grounded for several years due to structural concerns and trouble with the development of the flight control system.
One of the most ambitious requirements for the LCA was the specification that it would have "relaxed static stability" (RSS). Although Dassault had offered an analogue FCS system in 1988, the ADA recognised that digital flight control technology would soon supplant it. RSS technology was introduced in 1974 on the General Dynamics YF-16, which was the world's first production aircraft to be slightly aerodynamically unstable by design. Most aircraft are designed with "positive" static stability, which means they have a natural tendency to return to level and controlled flight in the absence of control inputs; however, this quality tends to oppose the pilot's efforts to manoeuvre. An aircraft with "negative" static stability (i.e., RSS), on the other hand, will quickly depart from level and controlled flight unless the pilot constantly works to keep it in trim; while this enhances manoeuvrability, it is very wearing on a pilot relying on a mechanical flight control system.
Development of a FBW flight control system requires extensive knowledge of flight control laws and the expensive writing of a considerable amount of software code for the flight control computers, as well as its integration with the avionics and other electronic systems. When the LCA programme was launched, FBW was a state-of-the-art technology and such a sensitive one that India could find no nation willing to export it. Therefore, in 1992 the LCA National Control Law (CLAW) team was set up by the National Aeronautics Laboratory to develop India's own version. The CLAW team's scientists and mathematicians were successful in developing their control laws, but could not test them since India did not possess advanced real-time ground simulators at that time. Accordingly, British Aerospace
(BAe) and Lockheed Martin
were brought in to help in 1993, but the effort required for the Aeronautical Development Establishment to code the control laws into the FCS software proved a much larger job than originally anticipated.
Specific control law problems were tested on BAE's simulators (and on HAL's, once theirs became available). As it was being developed, progressive elements of the coding were checked out on the "Minibird" and "Ironbird" test rigs at the ADE and HAL, respectively. A second series of inflight simulation tests of the integrated flight control software were conducted on the F-16 VISTA (Variable In-flight Stability Test Aircraft) simulator in the U.S. in July 1996, with 33 test flights being carried out. However, Lockheed Martin's involvement was terminated in 1998
as part of an embargo enacted by the U.S. in response to India's second nuclear tests
in May of that year.
The NAL's CLAW team eventually managed to successfully complete integration of the flight control laws indigenously, with the FCS software performing flawlessly for over 50 hours of pilot testing on TD-1, resulting in the aircraft being cleared for flight in early 2001. The LCA's maiden flight was made by TD-1 from National Flight Test Centre (NFTC), near Bangalore, on 4 January 2001, and its first successful supersonic flight followed on 1 August 2003. TD-2 made its first flight on 6 June 2002. 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.
Another critical technology area tackled for indigenous development by the ADA team is the Multi-Mode Radar (MMR). It was initially planned for the LCA to use the Ericsson Microwave Systems
PS-05/A I/J-band multi-function radar, which was developed by Ericsson and Ferranti Defence Systems Integration
for the Saab
JAS-39 Gripen
. However, after examining other radars in the early 1990s, the DRDO became confident that indigenous development was possible. HAL's Hyderabad division and the LRDE were selected to jointly lead the MMR program and the radar development effort began in 1997.
The DRDO's Centre for Airborne System (CABS) is responsible for running the test programme for the MMR. Between 1996 and 1997, CABS converted the surviving HAL/HS-748M
Airborne Surveillance Post (ASP) testbed into a testbed for the avionics and radar of the LCA. Known as the 'Hack', the only major structural modification besides the removal of the rotodome assembly was the addition of the LCA's nose cone in order to accommodate the MMR.
By mid-2002, development of the MMR was reported to be experiencing major delays and cost escalations. By early 2005 only the air-to-air look-up and look-down modes — two very basic modes — were confirmed to have been successfully tested. In May 2006 it was revealed that the performance of several modes being tested still "fell short of expectations." As a result, the ADA was reduced to running weaponisation tests with a weapon delivery pod, which is not a primary sensor, leaving critical tests on hold. According to test reports, the crux of the problem is a serious compatibility issue between the radar and the advanced signal processor module (SPM) built by the LRDE. Acquisition of an "off-the-shelf" foreign radar is an interim option being seriously considered.
turbofan
engine. Simultaneously, in 1986, a parallel programme to develop an indigenous powerplant was also launched. Led by the Gas Turbine Research Establishment
, the GTRE GTX-35VS
, named "Kaveri", was expected to replace the F404 on all production aircraft. However, progress in the Kaveri development programme was slowed by technical difficulties.
Development snags with the Kaveri resulted in the 2003 decision to procure the uprated F404-GE-IN20 engine for the eight pre-production LSP aircraft and two naval prototypes.General Electric was awarded a US$105 million contract in 2004 for development engineering and production of 17 -IN20 engines, delivery of which began in 2006.The F404-GE-IN20 was trial-installed on the Tejas and the engine generated more than 19,000 pounds (85 kN) uninstalled thrust and completed 330 hours of Accelerated Mission testing, equivalent of 1,000 hours of flight operation. In 2007, an additional 24 F404-IN20 afterburning engines were ordered to power the first operational squadron of Tejas fighters.
In mid-2004, the Kaveri failed its high-altitude tests in Russia, ending the last hopes of introducing it with the first production Tejas aircraft. In February 2006, the ADA awarded a contract to the French aircraft engine company Snecma
for technical assistance in working out the Kaveri's problems. The Kaveri engine based on Snecma’s new core, an uprated derivative of the M88-2 engine that powers the French Rafale fighter, providing 83-85 kilonewtons (KN) of maximum thrust was being considered a third option by DRDO which led the IAF to object that since Snecma had already developed the core of the engine it is offering the DRDO will not participate in any “joint development” but merely provide Snecma with an indigenous stamp.
In 2008, it was announced that the Kaveri would not be ready in time for the Tejas, and that an in-production powerplant would have to be selected in the 95 to 100 kilonewton (kN) (21,000–23,000 lbf) range to allow the aircraft to perform combat maneuvers with optimal weapons load. The contenders were the Eurojet EJ200
and the General Electric F414
. IAF sources said that the airframe will have to be redesigned to accommodate the heavier engine, which is to take up to three-four years.
After evaluation and acceptance of the technical offer provided by both Eurojet and GE Aviation, the commercial quotes were compared in detail and GE Aviation was declared as the lowest bidder. The deal will cover purchase of 99 GE F414 engines. The initial batch will be supplied by GE and the remainder will be manufactured in India under a transfer of technology arrangement.
In March 2005, the IAF placed a order for 20 aircraft, with a similar purchase of another 20 aircraft to follow. All 40 will be equipped with the F404-GE-IN20 engine. A 14 member "LCA Induction Team" was formed at Bangalore
to prepare the Tejas for service and assist in its introduction to service and support preparations for Tejas to receive Initial Operating Clearance
(IOC)
The first production variant of the 'Tejas' (LSP-1) flew on June 2008. Tejas completed 1000 Test Flights by January, 2009 with more than 530 hours of in-flight testing. By February 2009 officials of the Aeronautical Development Agency
stated that the Tejas had started flying with weapons and integration of radars would be completed by March 2009. In addition, they stated that nearly all system development activity would be completed by that time. In April 2010, the third production aircraft (LSP-3) flew with a hybrid version of the Elta
EL/M-2032
multi-mode radar, and by June 2010, the fourth production aircraft took flight in the configuration it would be delivered to the Indian Air Force in.
By June 2010, Tejas had also completed the second phase of hot weather trials. The objective of the hot weather trials was to prove that the aircraft was in an IOC configuration with the weapon system and sensors integrated. The sea trials of the aircraft are also being carried out. LSP-5 with IOC standard equipment took to skies on November 19, 2010.
The trainer variant prototype took to the skies in November 2009. In December 2009, the Indian government
sanctioned to begin production of the fighter jet for the Indian Air Force and Indian Navy. The Indian Navy has a requirement of 50 Tejas and the first prototype, NP-1 was rolled out in July 2010. IAF ordered 20 additional Tejas fighters after the defence acquisition council cleared the plan.
Initial Operating Clearance (IOC) for the Tejas was awarded on 10 January 2011 by Defence Minister A K Antony to Chief of Air Staff Air Chief Marshal P V Naik. IOC allows IAF pilots to use the aircraft.The IAF
plans to raise the first squadron in Bengaluru
to iron out issues with ADA and HAL, and eventually base these fighters at a new airbase in Sulur
in the southern state of Tamil Nadu
. The first squadron is expected to be established by 2013.
The IAF officially accepted its first Tejas fighter on 21 March 2011. The Tejas is planned to be cleared for operational service by late 2012. The weapon tests including bombing begun in September 2011 at Pokhran range, to be followed by missile firing tests at Goa.
It was reported on 03 October 2011 that the Tejas' Final Operational Clearance (FOC) has been delayed by almost one year to December 2013.
The Tejas is single-engined multirole fighter which features a tailless, compound delta planform
and is designed with "relaxed static stability" for enhanced maneuverability. Originally intended to serve as an air superiority aircraft with a secondary "dumb bomb" ground-attack role, the flexibility of this design approach has permitted a variety of guided air-to-surface and anti-shipping weapons to be integrated for more well-rounded multirole and multimission capabilities.
The tailless, compound-delta planform is designed to keep the Tejas small and lightweight. The use of this planform also minimises the control surfaces needed (no tailplane
s or foreplanes, just a single vertical tailfin), permits carriage of a wider range of external stores, and confers better close-combat, high-speed, and high-alpha
performance characteristics than comparable cruciform-wing designs. Extensive wind tunnel testing on scale models and complex computational fluid dynamics
analyses have optimised the aerodynamic configuration of the LCA, giving it minimum supersonic drag
, a low wing-loading
, and high rates of roll and pitch.
All weapons are carried on one or more of seven hardpoints with total capacity of greater than 4,000 kg: three stations under each wing and one on the under-fuselage
centreline. There is also an eighth, offset station beneath the port-side intake
trunk which can carry a variety of pods (FLIR
, IRST
, laser rangefinder/designator
, or reconnaissance
), as can the centreline under-fuselage station and inboard pairs of wing stations.
The Tejas has integral internal fuel tank
s to carry 3,000 kg of fuel in the fuselage and wing, and a fixed inflight refuelling probe
on the starboard side of the forward fuselage. Externally, there are "wet" hardpoint provisions for up to three 1,200- or five 800-litre (320- or 210-US gallon; 260- or 180-Imp gallon) fuel tanks on the inboard and mid-board wing stations and the centreline fuselage station.
s, 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
(doors and skins), wings (skin, spars and ribs), elevon
s, 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 joint
s or rivet
s, which increases the aircraft's reliability and lowers its susceptibility to structural fatigue
cracks.
The tailfin for the LCA is a monolithic honeycomb piece, an approach which reduced its manufacturing cost by 80% compared to the customary "subtractive" or "deductive" method, whereby the shaft is carved out of a block of titanium alloy by a computerized numerically controlled machine
. No other manufacturer is known to have made fins out of a single piece. A 'nose' for the rudder is added by 'squeeze' riveting.
The use of composites in the LCA resulted in a 40% reduction in the total number of parts compared to using a metallic frame. Furthermore, the number of fastener
s has been reduced by half in the composite structure from the 10,000 that would have been required in a metallic frame design. The composite design also helped to avoid about 2,000 holes being drilled into the airframe. Overall, the aircraft's weight is lowered by 21%. While each of these factors can reduce production costs, an additional benefit — and significant cost savings — is realised in the shorter time required to assemble the aircraft — seven months for the LCA as opposed to 11 months using an all-metal airframe.
The airframe of the naval variant of the Tejas will be modified with a nose droop to provide improved view during landing approach, and wing leading edge
vortex controllers (LEVCON) to increase lift during approach. The LEVCONs are control surfaces that extend from the wing-root leading edge and thus afford better low-speed handling for the LCA, which would otherwise be slightly hampered due to the increased drag that results from its delta-wing design. As an added benefit, the LEVCONs will also increase controllability at high angles of attack
(AoA).
The naval Tejas will also have a strengthened spine, a longer and stronger undercarriage
, and powered nose wheel steering for deck manoeuvrability. The Tejas trainer variant will have "aerodynamic commonality" with the two-seat naval aircraft design.
with a pair of single inward-retracting mainwheels and a steerable, twin-wheel forward-retracting nose gear. The landing gear was originally to have been imported, but following the imposition of trade sanctions, HAL developed the entire system independently.
to ease handling by the pilot. The Tejas aerodynamic configuration is based on a pure delta-wing layout with shoulder-mounted wing
s. Its control surfaces are all hydraulically actuated. The wing's outer leading edge incorporates three-section slats
, while the inboard sections have additional slats to generate vortex lift
over the inner wing and high-energy air-flow along the tail fin
to enhance high-AoA stability and prevent departure from controlled flight. The wing trailing edge is occupied by two-segment elevon
s to provide pitch and roll control
. The only empennage
-mounted control surfaces are the single-piece rudder and two airbrakes
located in the upper rear part of the fuselage, one each on either side of the fin.
The digital FBW system of the Tejas employs a powerful digital flight control computer
(DFCC) comprising four computing channels, each with its own independent power supply
and all housed in a single LRU
. The DFCC receives signals from a variety of sensors and pilot control stick inputs, and processes these through the appropriate channels to excite and control the elevons, rudder and leading edge slat hydraulic actuators. The DFCC channels are built around 32-bit microprocessor
s and use a subset of the Ada
programming language
for software implementation. The computer interfaces with pilot display elements like the MFDs through MIL-STD-1553
B multiplex avionics data buses
and RS-422 serial links.
The wing-shielded, side-mounted bifurcated, fixed-geometry Y-duct air intake
s have an optimised diverter configuration to ensure buzz-free air supply to the engine at acceptable distortion levels, even at high AoA.
The original plan was for the LCA prototype aircraft to be equipped with the General Electric F404-GE-F2J3 afterburning turbofan engine, while the production aircraft would be fitted with the indigenous GTRE GTX-35VS Kaveri turbofan being developed in a parallel. Continued development snags with the Kaveri resulted in a 2003 decision to procure the uprated GE F404-IN20 engine for the eight pre-production LSP aircraft and two naval prototypes and after accelerated trials an order was placed for 24 more IN20 engines for installation on the first 20 production aircraft. The Tejas Mark II will be equipped with the GE F414 engine.
(NVG)-compatible "glass cockpit
" that is dominated by an CSIR-CSIO developed 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 (providing the pilot with essential flight information in case of an emergency). The CSIO-developed HUD, Elbit
-furnished DASH helmet-mounted display and sight (HMDS), and hands-on-throttle-and-stick
(HOTAS) controls 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 MFDs provide information on the engine, hydraulics
, electrical, flight control, and environmental control systems on a need-to-know basis, along with basic flight and tactical information. Dual redundant display processors produce 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.
Target acquisition is accomplished through a state-of-the-art radar — potentially supplemented by a laser designator
pod, forward-looking infra-red
(FLIR) or other opto-electronic sensors — to 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. The LCA also has secure and jam-resistant communication systems such as the IFF
transponder/interrogator
, VHF/UHF
radios, and air-to-air/air-to-ground datalinks
. The ADA Systems Directorate's Integrated Digital Avionics Suite (IDAS) integrates the flight controls, environmental controls, aircraft utilities systems management, stores management system (SMS), etc. on three 1553B buses by a centralised 32-bit, high-throughput mission computer.
Multi-Mode Radar in development is designed to keep track of a maximum of 10 targets and allows simultaneous multiple-target engagement. Jointly developed by the LRDE and HAL Hyderabad, the MMR 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.
While originally planned to be fitted on production aircraft, delays in the development of MMR prompted the DRDO to co-operate with Israel Aerospace Industries to integrate a Hybrid version of the EL/M-2032
radar for use with Tejas. The EL/M-2032 radar used in LSP-3 has a detection and tracking range of up to 150 km in air-to-air mode, the air-to-ground mode generates high resolution radar imagery of locations at up to 150 km, and air-to-sea mode can detect and classify naval targets at ranges of up to 300 km.
The development of an AESA radar for the Tejas is expected to begin pending the selection of a developmental partner. The contenders for the contract are the European Consortium EADS
and the Israeli company Elta
. The initial contract will see the co-development of 10 prototypes.
suite is designed to enhance the Tejas survivability
during deep penetration and combat. The LCA's EW suite is developed by the Defence Avionics Research Establishment (DARE) with support from the Defence Electronics Research Laboratory (DLRL). This EW suite, known as "Mayavi"(Illusionist), includes a radar warning receiver
(RWR), self-protection jammer
, laser warning system, missile approach warning system, and chaff/flare dispenser
. In the interim, the Indian Defence Ministry has revealed that an unspecified number of EW suites had been purchased from Israel's Elisra
for the LCA prototypes.
The ADA claims that a degree of "stealth
" has been designed into the Tejas. 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 missile
s (AAM), and surface-to-air missile
(SAM) defence systems.
zero-zero ejection seat. The British Martin-Baker ejection seat is planned to be replaced with a locally-developed alternative. To improve pilot safety during ejection, the Armament Research and Development Establishment (ARDE), Pune, India
created a new line-charged canopy severance system, which has been certified by Martin-Baker.
, Bangalore. It was inaugurated by deputy chief of air staff of Indian Air Force
. It has been used to provide design support during the initial phase of LCA development in particular handling quality evaluation and planning and practicing mission profiles.
Aircraft already built and projected models to be built. Model designations, tail numbers and dates of first flight are shown.
Technology Demonstrators (TD)
Prototype Vehicles (PV)
Naval Prototypes (NP)
Limited Series Production (LSP) aircraft
Currently, 8 LSP series aircraft plus 40 aircraft are on order.
before being moved to Sulur
.
Features and analysis:
Technical:
General:
Multirole combat aircraft
A multirole combat aircraft is an aircraft designed to act in at least two different roles in combat. The primary role is usually a fighter—hence, it is as often called a multirole fighter—while the secondary role is usually air-to-surface attack. More roles are added, such as air reconnaissance,...
developed by India. It is a tailless, compound delta-wing design powered by a single engine. It came from the Light Combat Aircraft (LCA) programme, which began in the 1980s to replace India's ageing MiG-21
Mikoyan-Gurevich MiG-21
The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. It was popularly nicknamed "balalaika", from the aircraft's planform-view resemblance to the Russian stringed musical instrument or ołówek by Polish pilots due to...
fighters. Later the LCA was officially named "Tejas" by then Prime Minister
Prime Minister of India
The Prime Minister of India , as addressed to in the Constitution of India — Prime Minister for the Union, is the chief of government, head of the Council of Ministers and the leader of the majority party in parliament...
Atal Bihari Vajpayee
Atal Bihari Vajpayee
Atal Bihari Vajpayee is an Indian statesman who served as the tenth Prime Minister of India three times – first for a brief term of 13 days in 1996, and then for two terms from 1998 to 2004. After his first brief period as Prime Minister in 1996, Vajpayee headed a coalition government from...
.
The Tejas has the delta wing configuration, with no tailplanes or foreplanes, and features a single vertical fin. It integrates technologies such as relaxed static stability
Relaxed stability
In aviation, relaxed stability is the tendency of an aircraft to change its attitude and angle of bank of its own accord. An aircraft with relaxed stability will oscillate in simple harmonic motion around a particular attitude at an increasing amplitude....
, fly-by-wire flight control system
Fly-by-wire
Fly-by-wire is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals transmitted by wires , and flight control computers determine how to move the actuators at each control...
, advanced digital cockpit, multi-mode radar, integrated digital avionics system, advanced composite material structures and a flat rated
Flat rated
When an engine is Flat rated it means that an engine of high Horsepower rating is constrained to a lower horsepower rating. The engine output in this case will always remain the same, but when atmospheric conditions such as high temperatures and high altitude reduce the power output of the engine...
engine. The IAF is reported to have a requirement for 200 single-seat and 20 two-seat conversion trainers, while the Indian Navy may order up to 40 single-seaters to replace its Sea Harrier FRS.51
BAE Sea Harrier
The British Aerospace Sea Harrier is a naval VTOL/STOVL jet fighter, reconnaissance and attack aircraft, a development of the Hawker Siddeley Harrier. It first entered service with the Royal Navy in April 1980 as the Sea Harrier FRS1 and became informally known as the "Shar"...
and Harrier T.60.
The Tejas achieved a speed of over 1350 kilometres per hour (838.9 mph) per hour during its sea level flight trials, thus becoming the second supersonic fighter manufactured indigenously by Hindustan Aeronautics Limited after the HAL Marut. The Tejas was cleared in January 2011 for use by Indian Air Force pilots. It will not reach final operational clearance until 2014.
LCA programme
In 1969, the Indian government accepted the recommendation by its Aeronautics Committee that Hindustan Aeronautics LimitedHindustan Aeronautics Limited
Hindustan Aeronautics Limited based in Bangalore, India, is one of Asia's largest aerospace companies. Under the management of the Indian Ministry of Defence, this state-owned company is mainly involved in aerospace industry, which includes manufacturing and assembling aircraft, navigation and...
(HAL) should design and develop an advanced technology fighter aircraft around a proven engine. Based on a 'Tactical Air Support Aircraft' ASR markedly similar to that for the Marut, HAL completed design studies in 1975, but the project fell through due to inability to procure the selected "proven engine" from a foreign manufacturer and the IAF's requirement for an air superiority fighter with secondary air support and interdiction capability remained unfulfilled.
In 1983 IAF realized the need of an indigenous combat aircraft for two primary purposes. The principal and most obvious goal was the development of a replacement aircraft for India's ageing MiG-21 fighters. The MiG-21 has been the mainstay of the Indian Air Force
Indian Air Force
The Indian Air Force is the air arm of the Indian armed forces. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict...
since the 1970s. The "Long Term Re-Equipment Plan 1981" noted that the MiG-21s would be approaching the end of their service lives by the mid-1990s, and that by 1995 the IAF would lack 40% of the aircraft needed to fill its projected force structure requirements.
The LCA programme's other main objective was to serve as the vehicle for an across-the-board advancement of India's domestic aerospace
Aerospace
Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...
industry. The value of the aerospace "self-reliance" initiative is not simply the production of an aircraft, but also the building of a local industry
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...
capable of creating state-of-the-art
State of the art
The state of the art is the highest level of development, as of a device, technique, or scientific field, achieved at a particular time. It also refers to the level of development reached at any particular time as a result of the latest methodologies employed.- Origin :The earliest use of the term...
products with commercial spin-offs for a global market. The LCA program was intended in part to further expand and advance India's indigenous aerospace capabilities.
To better accomplish these goals, the government chose to take a different management approach, and in 1984 established the Aeronautical Development Agency
Aeronautical Development Agency
The Aeronautical Development Agency of India's Ministry of Defence was established in Bangalore in 1984 to oversee the development of the nation's Light Combat Aircraft programme.- Airframe :...
(ADA) to manage the LCA programme.Although the Tejas is most often described as a product of Hindustan Aeronautics Limited
Hindustan Aeronautics Limited
Hindustan Aeronautics Limited based in Bangalore, India, is one of Asia's largest aerospace companies. Under the management of the Indian Ministry of Defence, this state-owned company is mainly involved in aerospace industry, which includes manufacturing and assembling aircraft, navigation and...
(HAL), responsibility for the development of the Tejas actually belongs to ADA, a national consortium of over 100 defence laboratories, industrial organisations, and academic institutions with HAL being the principal contractor.
The Indian government's "self-reliance" goals for the LCA include indigenous development of the three most sophisticated — and hence most challenging — systems: the fly-by-wire (FBW) flight control system
Aircraft flight control systems
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...
(FCS), multi-mode pulse-doppler radar
Pulse-doppler radar
Pulse-Doppler is a 4D radar system capable of detecting both target 3D location as well as measuring radial velocity . It uses the Doppler effect to avoid overloading computers and operators as well as to reduce power consumption...
, and afterburning turbofan engine
Turbofan
The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...
. Although India has had a policy of strictly limiting foreign participation in the LCA programme, these are the only major LCA systems on which the ADA has had to invite significant foreign technological assistance and consultancy. Moreover, the engine and radar are also the only major systems for which the ADA has seriously considered substituting foreign equipment.
The ambitiousness of the LCA programme in terms of pursuing self-reliance in aviation technologies is illustrated by the fact that out of a total of 35 major avionics
Avionics
Avionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
components and line-replaceable unit
Line-replaceable unit
A line-replaceable unit is a modular component of an airplane, ship or spacecraft that is designed to be replaced quickly at an operating location. An LRU is usually a sealed unit such as a radio or other auxiliary equipment...
s (LRUs), only three involve foreign systems. These are the multi-function display
Multi-function display
A Multi-function display is a small screen in an aircraft surrounded by multiple buttons that can be used to display information to the pilot in numerous configurable ways. Often an MFD will be used in concert with a Primary Flight Display. MFDs are part of the digital era of modern planes or...
s (MFDs) by Sextant (France) and Elbit
Elbit Systems
Elbit Systems Ltd. is one of the world's largest defense electronics manufacturers and integrators. Established in 1967, and based in Haifa, Israel, Elbit employs 11,000 people worldwide....
(Israel), the helmet-mounted display and sight (HMDS) cueing system by Elbit, and the laser pod supplied by Rafael
RAFAEL Armament Development Authority
Rafael Advanced Defense Systems Ltd. , known as RAFAEL or Rafael, is an Israeli defense technology company...
(Israel). However, even among these three, when the LCA reaches the production stage, the MFDs are expected to be supplied by Indian companies. A few other important items of equipment (such as the Martin-Baker ejection seat) have been imported. As a consequence of the embargo imposed on India after its nuclear weapons tests
Pokhran-II
Pokharan-II refers to test explosions of five nuclear devices, three on 11 May and two on 13 May 1998, conducted by India at the Pokhran test range. These nuclear tests resulted in a variety of sanctions against India by a number of major states....
in May 1998, many items originally planned to be imported were instead developed indigenously .
Of the five critical technologies the ADA identified at the beginning of the LCA programme as needing to be mastered for India to be able 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
Glass cockpit
A glass cockpit is an aircraft cockpit that features electronic instrument displays, typically large LCD screens, as opposed to the traditional style of analog dials and gauges...
." 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
Airbus
Airbus SAS is an aircraft manufacturing subsidiary of EADS, a European aerospace company. Based in Blagnac, France, surburb of Toulouse, and with significant activity across Europe, the company produces around half of the world's jet airliners....
and Infosys
Infosys
Infosys Limited, formerly Infosys Technologies Limited is a global technology services company headquartered in Bangalore, India. It is the second largest IT exporter in India with 133,560 employees as of March 2011. It has offices in 33 countries and development centers in India, China,...
). These successes have gone mostly unnoticed in the shadow of the problems encountered with the other three key technology initiatives. Nonetheless, as a result of the accomplishments of India's domestic industries, presently about 70% of the components in LCA are manufactured in India and the dependence on imported components used would be progressively reduced in the coming years.
HAL serves as the prime contractor and has leading responsibility for LCA design, systems integration, airframe manufacturing, aircraft final assembly, flight testing, and service support. The ADA itself has primary responsibility for the design and development of the LCA's avionics suite and its integration with the flight controls, environmental controls, aircraft utilities systems management, stores management system, etc.
Of particular importance are the initiatives to develop an indigenous flight control system, radar, and engine for the LCA. The National Aeronautics Laboratory (NAL)—now called the National Aerospace Laboratories
National Aerospace Laboratories
National Aerospace Laboratories , is India's second largest aerospace firm after Hindustan Aeronautics . It was established by the Council of Scientific and Industrial Research at Delhi in 1959 and its headquarters was later moved to Bangalore in 1960...
—was selected to lead the development of the flight control laws, supported by the Aeronautical Development Establishment
Aeronautical Development Establishment
The Aeronautical Development Establishment is a laboratory of India's Defence Research and Development Organisation . Located in Bangalore, its primary function is research and development in the field of military aviation....
(ADE). HAL and the Electronics and Radar Development Establishment (LRDE) are jointly developing the Tejas Multi-Mode Radar (MMR). The GTRE is responsible for the design and parallel development of the GTX-35VS Kaveri
GTRE GTX-35VS Kaveri
The GTRE GTX-35VS Kaveri is an afterburning turbofan being developed by the Gas Turbine Research Establishment , a lab under the DRDO in Bangalore, India...
afterburning turbofan engine for the Tejas.
The IAF's Air Staff Requirement for the LCA were not finalised until October 1985. This delay rendered moot the original schedule which called for first flight in April 1990 and service entry in 1995; however, it also proved a boon as it is gave the ADA time to better marshal national R&D and industrial resources, recruit personnel, create infrastructure, and to gain a clearer perspective of which advanced technologies could be developed indigenously and which would need to be imported.
Project definition commenced in October 1987 and was completed in September 1988. Dassault Aviation
Dassault Aviation
Dassault Aviation is a French aircraft manufacturer of military, regional and business jets, a subsidiary of Dassault Group.It was founded in 1930 by Marcel Bloch as Société des Avions Marcel Bloch or "MB". After World War II, Marcel Bloch changed his name to Marcel Dassault, and the name of the...
of France was hired as a consultant to review the PD and provide advice based on its extensive aviation expertise. The PD phase is a critical early element in the aircraft design and development process because from this flow key elements of the detailed design, manufacturing approach, and maintenance requirements.
Development history
The LCA design was finalised in 1990 as a small tail-less delta wingDelta wing
The delta wing is a wing planform in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta .-Delta-shaped stabilizers:...
ed machine with relaxed static stability (RSS) to enhance maneuverability performance. The sophisticated avionics and advanced composite structure specified caused some concern almost immediately, and the IAF expressed doubt that India possessed sufficient technological infrastructure to support such an ambitious project. A governmental review committee was formed in May 1989 which reported out a general view that Indian infrastructure, facilities and technology had advanced sufficiently in most areas to undertake the project. As a measure of prudence, though, it was decided that the full-scale engineering development (FSED) stage of the programme would proceed in two stages.
Phase 1 would focus on "proof of concept
Proof of concept
A proof of concept or a proof of principle is a realization of a certain method or idea to demonstrate its feasibility, or a demonstration in principle, whose purpose is to verify that some concept or theory that has the potential of being used...
" and would comprise the design, development and testing (DDT) of two technology demonstrator aircraft (TD-1 and TD-2) and fabrication of a structural test specimen (STS) airframe; only after successful testing of the TD aircraft would the Indian government give its full support to the LCA design. This would be followed by the production of two prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
vehicles (PV-1 and PV-2), and creation of the necessary basic infrastructure and test facilities for the aircraft would begin.
Phase 2 would consist of the manufacturing of three more prototype vehicles (PV-3 as the production variant, PV-4 as the naval variant, and PV-5 as the trainer variant) and a fatigue test specimen, and the construction of further development and test facilities at various work centres.
Phase 1 commenced in 1990 and HAL started work on the technology demonstrators in mid-1991; however, a financial crunch resulted in full-scale funding not being authorized until April 1993, with significant work on FSED Phase 1 commencing in June. The first technology demonstrator, TD-1, was rolled out on 17 November 1995 and was followed by TD-2 in 1998, but they were kept grounded for several years due to structural concerns and trouble with the development of the flight control system.
One of the most ambitious requirements for the LCA was the specification that it would have "relaxed static stability" (RSS). Although Dassault had offered an analogue FCS system in 1988, the ADA recognised that digital flight control technology would soon supplant it. RSS technology was introduced in 1974 on the General Dynamics YF-16, which was the world's first production aircraft to be slightly aerodynamically unstable by design. Most aircraft are designed with "positive" static stability, which means they have a natural tendency to return to level and controlled flight in the absence of control inputs; however, this quality tends to oppose the pilot's efforts to manoeuvre. An aircraft with "negative" static stability (i.e., RSS), on the other hand, will quickly depart from level and controlled flight unless the pilot constantly works to keep it in trim; while this enhances manoeuvrability, it is very wearing on a pilot relying on a mechanical flight control system.
Development of a FBW flight control system requires extensive knowledge of flight control laws and the expensive writing of a considerable amount of software code for the flight control computers, as well as its integration with the avionics and other electronic systems. When the LCA programme was launched, FBW was a state-of-the-art technology and such a sensitive one that India could find no nation willing to export it. Therefore, in 1992 the LCA National Control Law (CLAW) team was set up by the National Aeronautics Laboratory to develop India's own version. The CLAW team's scientists and mathematicians were successful in developing their control laws, but could not test them since India did not possess advanced real-time ground simulators at that time. Accordingly, British Aerospace
British Aerospace
British Aerospace plc was a UK aircraft, munitions and defence-systems manufacturer. Its head office was in the Warwick House in the Farnborough Aerospace Centre in Farnborough, Hampshire...
(BAe) and Lockheed Martin
Lockheed Martin
Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....
were brought in to help in 1993, but the effort required for the Aeronautical Development Establishment to code the control laws into the FCS software proved a much larger job than originally anticipated.
Specific control law problems were tested on BAE's simulators (and on HAL's, once theirs became available). As it was being developed, progressive elements of the coding were checked out on the "Minibird" and "Ironbird" test rigs at the ADE and HAL, respectively. A second series of inflight simulation tests of the integrated flight control software were conducted on the F-16 VISTA (Variable In-flight Stability Test Aircraft) simulator in the U.S. in July 1996, with 33 test flights being carried out. However, Lockheed Martin's involvement was terminated in 1998
1998 in aviation
This is a list of aviation-related events from 1998:-Events:* Cirrus Aircraft successfully flight-tests the CAPS ballistic emergency aircraft parachute.* Adam Aircraft Industries founded* Eclipse Aviation founded-January:...
as part of an embargo enacted by the U.S. in response to India's second nuclear tests
Pokhran-II
Pokharan-II refers to test explosions of five nuclear devices, three on 11 May and two on 13 May 1998, conducted by India at the Pokhran test range. These nuclear tests resulted in a variety of sanctions against India by a number of major states....
in May of that year.
The NAL's CLAW team eventually managed to successfully complete integration of the flight control laws indigenously, with the FCS software performing flawlessly for over 50 hours of pilot testing on TD-1, resulting in the aircraft being cleared for flight in early 2001. The LCA's maiden flight was made by TD-1 from National Flight Test Centre (NFTC), near Bangalore, on 4 January 2001, and its first successful supersonic flight followed on 1 August 2003. TD-2 made its first flight on 6 June 2002. The automatic flight control system
Aircraft flight control systems
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...
(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.
Another critical technology area tackled for indigenous development by the ADA team is the Multi-Mode Radar (MMR). It was initially planned for the LCA to use the Ericsson Microwave Systems
Ericsson
Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...
PS-05/A I/J-band multi-function radar, which was developed by Ericsson and Ferranti Defence Systems Integration
Ferranti
Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...
for the Saab
Saab
Saab AB is a Swedish aerospace and defence company, founded in 1937. From 1947 to 1990 it was the parent company of automobile manufacturer Saab Automobile, and between 1968 and 1995 the company was in a merger with commercial vehicle manufacturer Scania, known as Saab-Scania.-History:"Svenska...
JAS-39 Gripen
JAS 39 Gripen
The Saab JAS 39 Gripen is a lightweight single-engine multirole fighter manufactured by the Swedish aerospace company Saab. It was designed to replace the Saab 35 Draken and 37 Viggen in the Swedish Air Force...
. However, after examining other radars in the early 1990s, the DRDO became confident that indigenous development was possible. HAL's Hyderabad division and the LRDE were selected to jointly lead the MMR program and the radar development effort began in 1997.
The DRDO's Centre for Airborne System (CABS) is responsible for running the test programme for the MMR. Between 1996 and 1997, CABS converted the surviving HAL/HS-748M
Airborne Surveillance Platform
The Airborne Surveillance Platform is an Indian defense project, initiated by the Defence Research and Development Organization, which aimed to produce an Airborne Early Warning System. Two prototypes were developed and flight tested for three years. The project was cancelled in 1999 after the...
Airborne Surveillance Post (ASP) testbed into a testbed for the avionics and radar of the LCA. Known as the 'Hack', the only major structural modification besides the removal of the rotodome assembly was the addition of the LCA's nose cone in order to accommodate the MMR.
By mid-2002, development of the MMR was reported to be experiencing major delays and cost escalations. By early 2005 only the air-to-air look-up and look-down modes — two very basic modes — were confirmed to have been successfully tested. In May 2006 it was revealed that the performance of several modes being tested still "fell short of expectations." As a result, the ADA was reduced to running weaponisation tests with a weapon delivery pod, which is not a primary sensor, leaving critical tests on hold. According to test reports, the crux of the problem is a serious compatibility issue between the radar and the advanced signal processor module (SPM) built by the LRDE. Acquisition of an "off-the-shelf" foreign radar is an interim option being seriously considered.
Engine and propulsion
Initially, it was decided to equip the prototype aircraft with the General Electric F404-GE-F2J3 afterburningAfterburner (engine)
An afterburner is an additional component added to some jet engines, primarily those on military supersonic aircraft. Its purpose is to provide a temporary increase in thrust, both for supersonic flight and for takeoff...
turbofan
Turbofan
The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...
engine. Simultaneously, in 1986, a parallel programme to develop an indigenous powerplant was also launched. Led by the Gas Turbine Research Establishment
Gas Turbine Research Establishment
Gas Turbine Research Establishment is a laboratory of the Defence Research and Development Organisation . Located in Bangalore, its primary function is research and development of aero gas-turbines for military aircraft...
, the GTRE GTX-35VS
GTRE GTX-35VS Kaveri
The GTRE GTX-35VS Kaveri is an afterburning turbofan being developed by the Gas Turbine Research Establishment , a lab under the DRDO in Bangalore, India...
, named "Kaveri", was expected to replace the F404 on all production aircraft. However, progress in the Kaveri development programme was slowed by technical difficulties.
Development snags with the Kaveri resulted in the 2003 decision to procure the uprated F404-GE-IN20 engine for the eight pre-production LSP aircraft and two naval prototypes.General Electric was awarded a US$105 million contract in 2004 for development engineering and production of 17 -IN20 engines, delivery of which began in 2006.The F404-GE-IN20 was trial-installed on the Tejas and the engine generated more than 19,000 pounds (85 kN) uninstalled thrust and completed 330 hours of Accelerated Mission testing, equivalent of 1,000 hours of flight operation. In 2007, an additional 24 F404-IN20 afterburning engines were ordered to power the first operational squadron of Tejas fighters.
In mid-2004, the Kaveri failed its high-altitude tests in Russia, ending the last hopes of introducing it with the first production Tejas aircraft. In February 2006, the ADA awarded a contract to the French aircraft engine company Snecma
Snecma
Snecma is a major French manufacturer of engines for commercial and military aircraft, and for space vehicles. The name is an acronym for Société Nationale d'Étude et de Construction de Moteurs d'Aviation .In 2005, the Snecma group, which included Snecma ,...
for technical assistance in working out the Kaveri's problems. The Kaveri engine based on Snecma’s new core, an uprated derivative of the M88-2 engine that powers the French Rafale fighter, providing 83-85 kilonewtons (KN) of maximum thrust was being considered a third option by DRDO which led the IAF to object that since Snecma had already developed the core of the engine it is offering the DRDO will not participate in any “joint development” but merely provide Snecma with an indigenous stamp.
In 2008, it was announced that the Kaveri would not be ready in time for the Tejas, and that an in-production powerplant would have to be selected in the 95 to 100 kilonewton (kN) (21,000–23,000 lbf) range to allow the aircraft to perform combat maneuvers with optimal weapons load. The contenders were the Eurojet EJ200
Eurojet EJ200
|-See also:-External links:* * * * *...
and the General Electric F414
General Electric F414
The General Electric F414 is an afterburning turbofan engine in the 22,000 lbf thrust class produced by GE Aviation. The F414 was developed from GE's widely-used F404 turbofan for use in the Boeing F/A-18E/F Super Hornet.-Origin:...
. IAF sources said that the airframe will have to be redesigned to accommodate the heavier engine, which is to take up to three-four years.
After evaluation and acceptance of the technical offer provided by both Eurojet and GE Aviation, the commercial quotes were compared in detail and GE Aviation was declared as the lowest bidder. The deal will cover purchase of 99 GE F414 engines. The initial batch will be supplied by GE and the remainder will be manufactured in India under a transfer of technology arrangement.
Recent development
Bangalore
Bengaluru , formerly called Bengaluru is the capital of the Indian state of Karnataka. Bangalore is nicknamed the Garden City and was once called a pensioner's paradise. Located on the Deccan Plateau in the south-eastern part of Karnataka, Bangalore is India's third most populous city and...
to prepare the Tejas for service and assist in its introduction to service and support preparations for Tejas to receive Initial Operating Clearance
Initial operating capability
Initial operating capability or Initial operational capability is the state achieved when a capability is available in its minimum usefully deployable form. The term is often used in government or military procurement....
(IOC)
The first production variant of the 'Tejas' (LSP-1) flew on June 2008. Tejas completed 1000 Test Flights by January, 2009 with more than 530 hours of in-flight testing. By February 2009 officials of the Aeronautical Development Agency
Aeronautical Development Agency
The Aeronautical Development Agency of India's Ministry of Defence was established in Bangalore in 1984 to oversee the development of the nation's Light Combat Aircraft programme.- Airframe :...
stated that the Tejas had started flying with weapons and integration of radars would be completed by March 2009. In addition, they stated that nearly all system development activity would be completed by that time. In April 2010, the third production aircraft (LSP-3) flew with a hybrid version of the Elta
Elta
ELTA Systems LTD is an Israeli provider of defense products and services specializing in radar, C4ISTAR, RF, SIGINT and EW products.Elta, a group and subsidiary of Israel Aerospace Industries, is one of Israel's major defence electronics companies specializing in a variety of fields...
EL/M-2032
EL/M-2032
The EL/M-2032 is an advanced pulse Doppler, multimode Fire Control Radar intended for multi-role fighter aircraft originated from the Lavi project. It is suitable for air-to-air and air-to-surface modes....
multi-mode radar, and by June 2010, the fourth production aircraft took flight in the configuration it would be delivered to the Indian Air Force in.
By June 2010, Tejas had also completed the second phase of hot weather trials. The objective of the hot weather trials was to prove that the aircraft was in an IOC configuration with the weapon system and sensors integrated. The sea trials of the aircraft are also being carried out. LSP-5 with IOC standard equipment took to skies on November 19, 2010.
The trainer variant prototype took to the skies in November 2009. In December 2009, the Indian government
Government of India
The Government of India, officially known as the Union Government, and also known as the Central Government, was established by the Constitution of India, and is the governing authority of the union of 28 states and seven union territories, collectively called the Republic of India...
sanctioned to begin production of the fighter jet for the Indian Air Force and Indian Navy. The Indian Navy has a requirement of 50 Tejas and the first prototype, NP-1 was rolled out in July 2010. IAF ordered 20 additional Tejas fighters after the defence acquisition council cleared the plan.
Initial Operating Clearance (IOC) for the Tejas was awarded on 10 January 2011 by Defence Minister A K Antony to Chief of Air Staff Air Chief Marshal P V Naik. IOC allows IAF pilots to use the aircraft.The IAF
Indian Air Force
The Indian Air Force is the air arm of the Indian armed forces. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict...
plans to raise the first squadron in Bengaluru
Bangalore
Bengaluru , formerly called Bengaluru is the capital of the Indian state of Karnataka. Bangalore is nicknamed the Garden City and was once called a pensioner's paradise. Located on the Deccan Plateau in the south-eastern part of Karnataka, Bangalore is India's third most populous city and...
to iron out issues with ADA and HAL, and eventually base these fighters at a new airbase in Sulur
Sulur
Sulur is a town and one of a taluk in Coimbatore district. It is a suburb of Coimbatore, India. This is also a Legislative Constituency and is under the Coimbatore Parliament Constituency.-Demographics:...
in the southern state of Tamil Nadu
Tamil Nadu
Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...
. The first squadron is expected to be established by 2013.
The IAF officially accepted its first Tejas fighter on 21 March 2011. The Tejas is planned to be cleared for operational service by late 2012. The weapon tests including bombing begun in September 2011 at Pokhran range, to be followed by missile firing tests at Goa.
It was reported on 03 October 2011 that the Tejas' Final Operational Clearance (FOC) has been delayed by almost one year to December 2013.
Design
Planform
In aviation, a planform is the shape and layout of a fixed-wing aircraft's fuselage and wing. Of all the myriad planforms used, they can typically be grouped into those used for low-speed flight, found on general aviation aircraft, and those used for high-speed flight, found on many military...
and is designed with "relaxed static stability" for enhanced maneuverability. Originally intended to serve as an air superiority aircraft with a secondary "dumb bomb" ground-attack role, the flexibility of this design approach has permitted a variety of guided air-to-surface and anti-shipping weapons to be integrated for more well-rounded multirole and multimission capabilities.
The tailless, compound-delta planform is designed to keep the Tejas small and lightweight. The use of this planform also minimises the control surfaces needed (no tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...
s or foreplanes, just a single vertical tailfin), permits carriage of a wider range of external stores, and confers better close-combat, high-speed, and high-alpha
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...
performance characteristics than comparable cruciform-wing designs. Extensive wind tunnel testing on scale models and complex computational fluid dynamics
Computational fluid dynamics
Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with...
analyses have optimised the aerodynamic configuration of the LCA, giving it minimum supersonic drag
Wave drag
In aeronautics, wave drag is a component of the drag on aircraft, blade tips and projectiles moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects.- Overview :...
, a low wing-loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...
, and high rates of roll and pitch.
All weapons are carried on one or more of seven hardpoints with total capacity of greater than 4,000 kg: three stations under each wing and one on the under-fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
centreline. There is also an eighth, offset station beneath the port-side intake
Intake
An intake , or especially for aircraft inlet, is an air intake for an engine. Because the modern internal combustion engine is in essence a powerful air pump, like the exhaust system on an engine, the intake must be carefully engineered and tuned to provide the greatest efficiency and power...
trunk which can carry a variety of pods (FLIR
Forward looking infrared
Forward looking infrared cameras, typically used on military aircraft, use an imaging technology that senses infrared radiation.The sensors installed in forward looking infrared cameras, as well as those of other thermal imaging cameras, use detection of infrared radiation, typically emitted from a...
, IRST
Infra-red search and track
An infra-red search and track system is a method for detecting and tracking objects which give off infra-red radiation such as jet aircraft and helicopters. IRST is a generalized case of Forward Looking Infra-Red , i.e. from Forward-Looking to allround situational awareness...
, laser rangefinder/designator
Laser designator
A laser designator is a laser light source which is used to designate a target. Laser designators provide targeting for laser guided bombs, missiles, or precision artillery munitions, such as the Paveway series of bombs, Lockheed-Martin's Hellfire, or the Copperhead round, respectively.When a...
, or reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....
), as can the centreline under-fuselage station and inboard pairs of wing stations.
The Tejas has integral internal fuel tank
Fuel tank
A fuel tank is safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelled or released into an engine...
s to carry 3,000 kg of fuel in the fuselage and wing, and a fixed inflight refuelling probe
Aerial refueling
Aerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....
on the starboard side of the forward fuselage. Externally, there are "wet" hardpoint provisions for up to three 1,200- or five 800-litre (320- or 210-US gallon; 260- or 180-Imp gallon) fuel tanks on the inboard and mid-board wing stations and the centreline fuselage station.
Airframe
The LCA is constructed of aluminium-lithium alloyAlloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s, carbon-fibre composites
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
(C-FC), and titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
-alloy steels. The Tejas employs C-FC materials for up to 45% of its airframe by weight, including in the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
(doors and skins), wings (skin, spars and ribs), elevon
Elevon
Elevons are aircraft control surfaces that combine the functions of the elevator and the aileron , hence the name. They are frequently used on tailless aircraft such as flying wings. An elevon that is not part of the main wing, but instead is a separate tail surface, is a stabilator...
s, tailfin
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
, rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...
, air brakes
Air brake (aircraft)
In aeronautics, air brakes or speedbrakes are a type of flight control surface used on an aircraft to increase drag or increase the angle of approach during landing....
and landing gear
Landing Gear
Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
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 joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
s or rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...
s, which increases the aircraft's reliability and lowers its susceptibility to structural fatigue
Fatigue (material)
'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...
cracks.
The tailfin for the LCA is a monolithic honeycomb piece, an approach which reduced its manufacturing cost by 80% compared to the customary "subtractive" or "deductive" method, whereby the shaft is carved out of a block of titanium alloy by a computerized numerically controlled machine
Numerical control
Numerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...
. No other manufacturer is known to have made fins out of a single piece. A 'nose' for the rudder is added by 'squeeze' riveting.
Fastener
A fastener is a hardware device that mechanically joins or affixes two or more objects together.Fasteners can also be used to close a container such as a bag, a box, or an envelope; or they may involve keeping together the sides of an opening of flexible material, attaching a lid to a container,...
s has been reduced by half in the composite structure from the 10,000 that would have been required in a metallic frame design. The composite design also helped to avoid about 2,000 holes being drilled into the airframe. Overall, the aircraft's weight is lowered by 21%. While each of these factors can reduce production costs, an additional benefit — and significant cost savings — is realised in the shorter time required to assemble the aircraft — seven months for the LCA as opposed to 11 months using an all-metal airframe.
The airframe of the naval variant of the Tejas will be modified with a nose droop to provide improved view during landing approach, and wing leading edge
Leading edge
The leading edge is the part of the wing that first contacts the air; alternatively it is the foremost edge of an airfoil section. The first is an aerodynamic definition, the second a structural one....
vortex controllers (LEVCON) to increase lift during approach. The LEVCONs are control surfaces that extend from the wing-root leading edge and thus afford better low-speed handling for the LCA, which would otherwise be slightly hampered due to the increased drag that results from its delta-wing design. As an added benefit, the LEVCONs will also increase controllability at high angles of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...
(AoA).
The naval Tejas will also have a strengthened spine, a longer and stronger undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
, and powered nose wheel steering for deck manoeuvrability. The Tejas trainer variant will have "aerodynamic commonality" with the two-seat naval aircraft design.
Landing gear
The Tejas has a hydraulically retractable tricycle-type landing gearUndercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
with a pair of single inward-retracting mainwheels and a steerable, twin-wheel forward-retracting nose gear. The landing gear was originally to have been imported, but following the imposition of trade sanctions, HAL developed the entire system independently.
Flight controls
Since the Tejas is a relaxed static stability design, it is equipped with a quadruplex digital fly-by-wire flight control systemAircraft flight control systems
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...
to ease handling by the pilot. The Tejas aerodynamic configuration is based on a pure delta-wing layout with shoulder-mounted wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
s. Its control surfaces are all hydraulically actuated. The wing's outer leading edge incorporates three-section slats
Leading edge slats
Slats are aerodynamic surfaces on the leading edge of the wings of fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, so by deploying slats an aircraft can fly at slower...
, while the inboard sections have additional slats to generate vortex lift
Vortex lift
Vortex lift is a form of lift generated by delta wings operating at high angles of attack.-How it works:Vortex lift works by capturing vortices generated from the sharply swept leading edge of the wing. The vortex, formed roughly parallel to the leading edge of the wing, is trapped by the airflow...
over the inner wing and high-energy air-flow along the tail fin
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
to enhance high-AoA stability and prevent departure from controlled flight. The wing trailing edge is occupied by two-segment elevon
Elevon
Elevons are aircraft control surfaces that combine the functions of the elevator and the aileron , hence the name. They are frequently used on tailless aircraft such as flying wings. An elevon that is not part of the main wing, but instead is a separate tail surface, is a stabilator...
s to provide pitch and roll control
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
. The only empennage
Empennage
The empennage , also known as the tail or tail assembly, of most aircraft gives stability to the aircraft, in a similar way to the feathers on an arrow...
-mounted control surfaces are the single-piece rudder and two airbrakes
Air brake (aircraft)
In aeronautics, air brakes or speedbrakes are a type of flight control surface used on an aircraft to increase drag or increase the angle of approach during landing....
located in the upper rear part of the fuselage, one each on either side of the fin.
The digital FBW system of the Tejas employs a powerful digital flight control computer
Aircraft flight control systems
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...
(DFCC) comprising four computing channels, each with its own independent power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
and all housed in a single LRU
Line-replaceable unit
A line-replaceable unit is a modular component of an airplane, ship or spacecraft that is designed to be replaced quickly at an operating location. An LRU is usually a sealed unit such as a radio or other auxiliary equipment...
. The DFCC receives signals from a variety of sensors and pilot control stick inputs, and processes these through the appropriate channels to excite and control the elevons, rudder and leading edge slat hydraulic actuators. The DFCC channels are built around 32-bit microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s and use a subset of the Ada
Ada (programming language)
Ada is a structured, statically typed, imperative, wide-spectrum, and object-oriented high-level computer programming language, extended from Pascal and other languages...
programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
for software implementation. The computer interfaces with pilot display elements like the MFDs through MIL-STD-1553
MIL-STD-1553
MIL-STD-1553 is a military standard published by the United States Department of Defense that defines the mechanical, electrical, and functional characteristics of a serial data bus. It was originally designed for use with military avionics, but has also become commonly used in spacecraft on-board...
B multiplex avionics data buses
Computer bus
In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers.Early computer buses were literally parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same...
and RS-422 serial links.
Propulsion
Intake
An intake , or especially for aircraft inlet, is an air intake for an engine. Because the modern internal combustion engine is in essence a powerful air pump, like the exhaust system on an engine, the intake must be carefully engineered and tuned to provide the greatest efficiency and power...
s have an optimised diverter configuration to ensure buzz-free air supply to the engine at acceptable distortion levels, even at high AoA.
The original plan was for the LCA prototype aircraft to be equipped with the General Electric F404-GE-F2J3 afterburning turbofan engine, while the production aircraft would be fitted with the indigenous GTRE GTX-35VS Kaveri turbofan being developed in a parallel. Continued development snags with the Kaveri resulted in a 2003 decision to procure the uprated GE F404-IN20 engine for the eight pre-production LSP aircraft and two naval prototypes and after accelerated trials an order was placed for 24 more IN20 engines for installation on the first 20 production aircraft. The Tejas Mark II will be equipped with the GE F414 engine.
Avionics
The Tejas has a night vision gogglesNight vision goggles
A night vision device is an optical instrument that allows images to be produced in levels of light approaching total darkness. They are most often used by the military and law enforcement agencies, but are available to civilian users...
(NVG)-compatible "glass cockpit
Glass cockpit
A glass cockpit is an aircraft cockpit that features electronic instrument displays, typically large LCD screens, as opposed to the traditional style of analog dials and gauges...
" that is dominated by an CSIR-CSIO developed 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 (providing the pilot with essential flight information in case of an emergency). The CSIO-developed HUD, Elbit
Elbit Systems
Elbit Systems Ltd. is one of the world's largest defense electronics manufacturers and integrators. Established in 1967, and based in Haifa, Israel, Elbit employs 11,000 people worldwide....
-furnished DASH helmet-mounted display and sight (HMDS), and hands-on-throttle-and-stick
HOTAS
HOTAS, an abbreviation for Hands On Throttle-And-Stick, is the name given to the concept of placing buttons and switches on the throttle stick and flight control stick in an aircraft's cockpit, allowing the pilot to access vital cockpit functions and fly the aircraft without having to remove his...
(HOTAS) controls 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 MFDs provide information on the engine, hydraulics
Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
, electrical, flight control, and environmental control systems on a need-to-know basis, along with basic flight and tactical information. Dual redundant display processors produce computer-generated imagery
Computer-generated imagery
Computer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
on these displays. The pilot interacts with the complex avionics systems through a simple multifunction keyboard and function and sensor selection panels.
Target acquisition is accomplished through a state-of-the-art radar — potentially supplemented by a laser designator
Laser designator
A laser designator is a laser light source which is used to designate a target. Laser designators provide targeting for laser guided bombs, missiles, or precision artillery munitions, such as the Paveway series of bombs, Lockheed-Martin's Hellfire, or the Copperhead round, respectively.When a...
pod, forward-looking infra-red
Forward looking infrared
Forward looking infrared cameras, typically used on military aircraft, use an imaging technology that senses infrared radiation.The sensors installed in forward looking infrared cameras, as well as those of other thermal imaging cameras, use detection of infrared radiation, typically emitted from a...
(FLIR) or other opto-electronic sensors — to provide accurate target information to enhance kill probabilities. A ring laser gyro (RLG)-based inertial navigation system
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...
(INS) provides accurate navigation guidance to the pilot. The LCA also has secure and jam-resistant communication systems such as the IFF
Identification friend or foe
In telecommunications, identification, friend or foe is an identification system designed for command and control. It is a system that enables military and national interrogation systems to identify aircraft, vehicles, or forces as friendly and to determine their bearing and range from the...
transponder/interrogator
Secondary surveillance radar
Secondary surveillance radar is a radar system used in air traffic control , that not only detects and measures the position of aircraft i.e. range and bearing, but also requests additional information from the aircraft itself such as its identity and altitude...
, VHF/UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
radios, and air-to-air/air-to-ground datalinks
Data link
In telecommunication a data link is the means of connecting one location to another for the purpose of transmitting and receiving information. It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver and the interconnecting data telecommunication circuit...
. The ADA Systems Directorate's Integrated Digital Avionics Suite (IDAS) integrates the flight controls, environmental controls, aircraft utilities systems management, stores management system (SMS), etc. on three 1553B buses by a centralised 32-bit, high-throughput mission computer.
Radar
The coherent pulse-DopplerPulse-doppler radar
Pulse-Doppler is a 4D radar system capable of detecting both target 3D location as well as measuring radial velocity . It uses the Doppler effect to avoid overloading computers and operators as well as to reduce power consumption...
Multi-Mode Radar in development is designed to keep track of a maximum of 10 targets and allows simultaneous multiple-target engagement. Jointly developed by the LRDE and HAL Hyderabad, the MMR 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
Pulse repetition frequency
Pulse repetition frequency or Pulse repetition rate is the number of pulses per time unit . It is a measure or specification mostly used within various technical disciplines Pulse repetition frequency (PRF) or Pulse repetition rate (PRR) is the number of pulses per time unit (e.g. Seconds). It...
(PRF), platform motion compensation, doppler beam-sharpening, moving target indication
Moving target indication
Moving target indication is a mode of operation of a radar to discriminate a target against clutter. In contrast to another mode, stationary target indication, it takes an advantage of the fact that the target moves with respect to stationary clutter. The most common approach takes advantage of...
(MTI), Doppler filtering, constant false-alarm rate
Constant false alarm rate
Constant false alarm rate detection refers to a common form of adaptive algorithm used in radar systems to detect target returns against a background of noise, clutter and interference.Other detection algorithms are not adaptive...
(CFAR) detection, range-Doppler ambiguity resolution, scan conversion
Scan conversion
Scan conversion or scan rate converting is a video processing technique for changing the vertical / horizontal scan frequency of video signal for different purposes and applications...
, and online diagnostics to identify faulty processor modules.
While originally planned to be fitted on production aircraft, delays in the development of MMR prompted the DRDO to co-operate with Israel Aerospace Industries to integrate a Hybrid version of the EL/M-2032
EL/M-2032
The EL/M-2032 is an advanced pulse Doppler, multimode Fire Control Radar intended for multi-role fighter aircraft originated from the Lavi project. It is suitable for air-to-air and air-to-surface modes....
radar for use with Tejas. The EL/M-2032 radar used in LSP-3 has a detection and tracking range of up to 150 km in air-to-air mode, the air-to-ground mode generates high resolution radar imagery of locations at up to 150 km, and air-to-sea mode can detect and classify naval targets at ranges of up to 300 km.
The development of an AESA radar for the Tejas is expected to begin pending the selection of a developmental partner. The contenders for the contract are the European Consortium EADS
EADS
The European Aeronautic Defence and Space Company N.V. is a global pan-European aerospace and defence corporation and a leading defence and military contractor worldwide...
and the Israeli company Elta
Elta
ELTA Systems LTD is an Israeli provider of defense products and services specializing in radar, C4ISTAR, RF, SIGINT and EW products.Elta, a group and subsidiary of Israel Aerospace Industries, is one of Israel's major defence electronics companies specializing in a variety of fields...
. The initial contract will see the co-development of 10 prototypes.
Self-protection
The electronic warfareElectronic warfare
Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...
suite is designed to enhance the Tejas survivability
Survivability
Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts.-Engineering:In engineering, survivability is the quantified ability of a system, subsystem, equipment, process, or procedure to continue to function during and after a natural...
during deep penetration and combat. The LCA's EW suite is developed by the Defence Avionics Research Establishment (DARE) with support from the Defence Electronics Research Laboratory (DLRL). This EW suite, known as "Mayavi"(Illusionist), includes a radar warning receiver
Radar warning receiver
Radar warning receiver systems detect the radio emissions of radar systems. Their primary purpose is to issue a warning when a radar signal that might be a threat is detected. The warning can then be used, manually or automatically, to evade the detected threat...
(RWR), self-protection jammer
Radar jamming and deception
Radar jamming and deception is the intentional emission of radio frequency signals to interfere with the operation of a radar by saturating its receiver with noise or false information...
, laser warning system, missile approach warning system, and chaff/flare dispenser
Countermeasure
A countermeasure is a measure or action taken to counter or offset another one. As a general concept it implies precision, and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process...
. In the interim, the Indian Defence Ministry has revealed that an unspecified number of EW suites had been purchased from Israel's Elisra
Elisra
Elisra Group is an Israeli manufacturer of high-tech electronic devices for mainly but not exclusively military use. That includes equipment for electronic communication and surveillance, missile tracking and controlling systems, radar and lidar equipment. The group is composed of three companies:...
for the LCA prototypes.
The ADA claims that a degree of "stealth
Stealth technology
Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...
" has been designed into the Tejas. 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 missile
Air-to-air missile
An air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are typically powered by one or more rocket motors, usually solid fuelled but sometimes liquid fuelled...
s (AAM), and surface-to-air missile
Surface-to-air missile
A surface-to-air missile or ground-to-air missile is a missile designed to be launched from the ground to destroy aircraft or other missiles...
(SAM) defence systems.
Escape systems
Although two-seat variants of the LCA are planned, the examples built to date are crewed by a single pilot on a Martin-BakerMartin-Baker
Martin-Baker Aircraft Co. Ltd. is a manufacturer of ejection seats and safety related equipment for aviation. The company origins were as an aircraft manufacturer before becoming a pioneer in the field of ejection seats...
zero-zero ejection seat. The British Martin-Baker ejection seat is planned to be replaced with a locally-developed alternative. To improve pilot safety during ejection, the Armament Research and Development Establishment (ARDE), Pune, India
Pune
Pune , is the eighth largest metropolis in India, the second largest in the state of Maharashtra after Mumbai, and the largest city in the Western Ghats. Once the centre of power of the Maratha Empire, it is situated 560 metres above sea level on the Deccan plateau at the confluence of the Mula ...
created a new line-charged canopy severance system, which has been certified by Martin-Baker.
Flight simulator
To support the aircraft a dome-based Mission Simulator has been developed by the Aeronautical Development Establishment (ADE)Aeronautical Development Establishment
The Aeronautical Development Establishment is a laboratory of India's Defence Research and Development Organisation . Located in Bangalore, its primary function is research and development in the field of military aviation....
, Bangalore. It was inaugurated by deputy chief of air staff of Indian Air Force
Indian Air Force
The Indian Air Force is the air arm of the Indian armed forces. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict...
. It has been used to provide design support during the initial phase of LCA development in particular handling quality evaluation and planning and practicing mission profiles.
Prototypes
Aircraft already built and projected models to be built. Model designations, tail numbers and dates of first flight are shown.
Technology Demonstrators (TD)
- TD-1 (KH2001) - 4 Jan 2001
- TD-2 (KH2002) - 6 June 2002
Prototype Vehicles (PV)
- PV-1 (KH2003) - 25 November 2003
- PV-2 (KH2004) - 1 December 2005
- PV-3 (KH2005) - 1 December 2006 - This is the production variant.
- PV-4 - Originally planned to be a Naval variant for carrier operations, but now a second production variant.
- PV-5 (KH-T2009) - 26 November 2009 - Fighter/Trainer Variant
Naval Prototypes (NP)
- NP-1 - Two-seat Naval variant for carrier operations.Rolled out in July 2010 it will make its first flight by mid July 2011.
- NP-2 - Single-seat Naval variant for carrier operations.
Limited Series Production (LSP) aircraft
Currently, 8 LSP series aircraft plus 40 aircraft are on order.
- LSP-1 (KH2011) - 25 April 2007. This LCA is powered by F404-F2J3 Engine.
- LSP-2 (KH2012) - 16 June 2008. This is the first LCA fitted with F404-IN20 engine.
- LSP-3 23 April 2010. The first aircraft to have the Hybrid MMR radar and will be close to the IOC standard.
- LSP-4 (KH2014) - 2 June 2010 The first aircraft that was flown in the configuration that will be delivered to the Indian Air ForceIndian Air ForceThe Indian Air Force is the air arm of the Indian armed forces. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict...
In addition to the Hybrid MMR, the aircraft flew with a CountermeasureCountermeasureA countermeasure is a measure or action taken to counter or offset another one. As a general concept it implies precision, and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process...
Dispensing System and an identify friend or foeIdentification friend or foeIn telecommunications, identification, friend or foe is an identification system designed for command and control. It is a system that enables military and national interrogation systems to identify aircraft, vehicles, or forces as friendly and to determine their bearing and range from the...
electronic system. - LSP-5 (KH2015) - 19 November 2010 IOC standard with all sensor including night lighting in the cockpit, and an auto-pilot.
- LSP-6 - Will be used to increase the Angle of Attack. As well as develop better (Experimental) RAM coating to further reduce its radar signature.
- LSP-7 & LSP-8 - Will be soon given to IAF for user trials. LSP-7 by August 2011 and LSP-8 by December 2011.
- SP-1 to SP-40 - Planned to fly by late 2013. The SP-1 and SP-2 will be delivered by March 2012 and handed over to No.45 Squadron (Flying Daggers) that will be based initially in Bangalore, Karnataka.
- Total Test flights - 1746 as of November 2011.
Planned production variants
- Tejas Trainer – Two-seat operational conversion trainer for the Indian Air Force.
- Tejas Navy – Twin- and single-seat carrier-capable variants for the Indian Navy. The LCA's naval variant is to be ready for carrier trials by 2013 and is slated for deployment on the INS VikramadityaINS VikramadityaINS Vikramaditya is the new name for the former Soviet aircraft carrier Admiral Gorshkov, which has been procured by India, and is estimated to enter service in the Indian Navy after 2012....
as well as the Vikrant class aircraft carrier. It will be equipped for carrier operation with ski-jump take-off and arrested landing. It will include strengthened airframe and landing gear and the nose is drooped for better cockpit vision. - Tejas Mark 2 - Featuring more powerful General Electric F414-GE-INS6General Electric F414The General Electric F414 is an afterburning turbofan engine in the 22,000 lbf thrust class produced by GE Aviation. The F414 was developed from GE's widely-used F404 turbofan for use in the Boeing F/A-18E/F Super Hornet.-Origin:...
engine with 120 kN of thrust and refined aerodynamics. The Mark 2 is being developed to meet the Indian Air Force requirements and will incorporate 5th generation fighter elements which are intended to make way into FGFA and AMCA later.Tejas mk2 will now have a length of 14.2 metres (1-metre more than that of the Tejas Mk1 for incorporationg a stretched nose section and a modified fuselage section aft of the cockpit for housing an expanded complement of mission avionics LRUs), height of 4.6 metres (as opposed to 4.4 metres of the Tejas Mk1) to accommodate an enlarged vertical tail-section, and a wingspan of 8.2 metres—same as that of the Tejas Mk1—that, however, will feature an increased wing area. External stores capacity will be boosted to 5,000kg (as opposed to 3,500kg for the Tejas Mk1), while the twin internal air-intake ducts will be minimally enlarged to cater to the increased airflow requirements of the 120kN thrust F414-GE-INS6 turbofan built by GE Aero Engines. The Ministry of Defence had, last January, sanctioned US$542.44 million (Rs2,431.55-crore) for ADA to develop the IAF’s Tejas Mk2 variant and the Indian Navy’s LCA Mk2 (Navy) variant.The first Tejas Mk2 prototype will fly by December 2013, following which the MoD-owned Hindustan Aeronautics Ltd (HAL) would begin series-producing the MRCA by 2015. While the IAF is committed to procuring an initial 83 Tejas Mk2s, the Navy has expressed its firm requirement for 46 LCA Mk2 (Navy).
Operational history
The work to raise the first squadron started in July 2011. The Tejas will be inducted into the 45th squadron, the Flying Daggers and will be based in BangaloreBangalore
Bengaluru , formerly called Bengaluru is the capital of the Indian state of Karnataka. Bangalore is nicknamed the Garden City and was once called a pensioner's paradise. Located on the Deccan Plateau in the south-eastern part of Karnataka, Bangalore is India's third most populous city and...
before being moved to Sulur
Sulur
Sulur is a town and one of a taluk in Coimbatore district. It is a suburb of Coimbatore, India. This is also a Legislative Constituency and is under the Coimbatore Parliament Constituency.-Demographics:...
.
Operators
- Indian Air ForceIndian Air ForceThe Indian Air Force is the air arm of the Indian armed forces. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict...
- 40 LCA Mk.1 aircraft on order and plans to order LCA Mk.2 aircraft for 10 more squadrons (~180 total aircraft) after completion of LCA Mk.1 production. - Indian NavyIndian NavyThe Indian Navy is the naval branch of the armed forces of India. The President of India serves as the Commander-in-Chief of the Navy. The Chief of Naval Staff , usually a four-star officer in the rank of Admiral, commands the Navy...
- Signed an order for six Naval LCAs at an approximate cost of US$ 31.09 million per aircraft. The Indian Navy has a requirement for 50 Tejas aircraft.
Specifications (HAL Tejas)
See also
External links
Features and analysis:
- "Flying into the unknown" — A feature by The HinduThe HinduThe Hindu is an Indian English-language daily newspaper founded and continuously published in Chennai since 1878. According to the Audit Bureau of Circulations, it has a circulation of 1.46 million copies as of December 2009. The enterprise employed over 1,600 workers and gross income reached $40...
on the Tejas test pilotTest pilotA test pilot is an aviator who flies new and modified aircraft in specific maneuvers, known as flight test techniques or FTTs, allowing the results to be measured and the design to be evaluated....
s. - "LCA and Economics" by Sunil Sainis and George Joseph
- "The Light Combat Aircraft Story", by Air Marshal MSD Wollen (Retd).
- The case to support the indigenous LCA programme, by Ashok Parthasarathi and Raman Puri.
Technical:
- An Approach to High AoA Testing of the LCA
- Development Flight Testing of the Tejas Light Combat Aircraft
- LCA Avionics And Weapon System Mission Computer Software Development: A Case Study
General: