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| HAL Tejas |
The HAL Tejas is an Indian single-engine, fourth-generation, multirole light fighter designed by the Aeronautical Development Agency (ADA) in collaboration with Aircraft Research and Design Centre (ARDC) of Hindustan Aeronautics Limited (HAL) for the Indian Air Force and Indian Navy. It came from the Light Combat Aircraft (LCA) programme, which began in the 1980s to replace India's ageing MiG-21 fighters. In 2003, the LCA was officially named "Tejas".
Tejas has a tail-less compound delta-wing configuration with a single vertical stabilizer. This provides better high-alpha performance characteristics than conventional wing designs.[13] Its wing root leading edge has a sweep of 50 degrees, the outer wing leading edge has a sweep of 62.5 degrees, and trailing edge has a forward sweep of four degrees. It integrates technologies such as relaxed static stability, fly-by-wire flight control system, multi-mode radar, integrated digital avionics system and composite material structures. It is the smallest and lightest in its class of contemporary supersonic combat aircraft.
The Tejas is the second supersonic fighter developed by Hindustan Aeronautics Limited (HAL) after the HAL HF-24 Marut. Production of the Tejas Mark 1 for the Indian Air Force (IAF) began in 2016, at which time the naval version was undergoing flight tests for Indian Navy (IN). The projected requirement for the IAF was 200 single-seat fighters and 20 twin-seat trainers, while the IN expected to operate at least 40 single-seat fighters. The first Tejas IAF unit, No. 45 Squadron IAF Flying Daggers was formed on 1 July 2016 with two aircraft. Initially stationed at Bangalore, 45 Squadron was later relocated to its home base at Sulur, Tamil Nadu. The Minister of State for Defence, Subhash Bhamre, reported to parliament that the indigenous content of the Tejas was 59.7% by value and 75.5% by number of line replaceable units in 2016.
As of 2019, the Indian Air Force has planned for a total of 324 Tejas in several variants.The first batch of 40 Mark 1 aircraft consists of 16 Initial Operational Clearance (IOC) standard that were delivered in early 2019.[20] The delivery of the second batch of 16 Full Operational Clearance (FOC) standard aircraft commenced in late 2019 and led to formation of the second Tejas squadron — No. 18 Squadron IAF Flying Bullets — in Sulur on 27 May 2020.[21][5] The IAF will also go on to receive eight twin-seat trainers.The next 83 are to be to the upgraded Mark 1A standard.[22] By the time these first 123 are delivered, the Tejas Mark 2 is expected to be ready for series production by 2025–26.
Origins
In 1969, the Indian government accepted the recommendation by its Aeronautics Committee that Hindustan Aeronautics Limited (HAL) should design and develop a 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 realised the need for an Indian combat aircraft for two primary purposes. The principal and most obvious goal was to replace India's ageing MiG-21 fighters, which had been the mainstay of the IAF 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 percent of the aircraft needed to fill its projected force structure requirements. The LCA programme's other main objective was an across-the-board advancement of India's domestic aerospace industry.The value of the aerospace "self-reliance" initiative was not simply the aircraft's production, but also the building of a local industry capable of creating state-of-the-art products with commercial spin-offs for a global market.
In 1984, the Indian government chose to establish the Aeronautical Development Agency (ADA) to manage the LCA programme. While the Tejas is often described as a product of Hindustan Aeronautics Limited (HAL), responsibility for its development belongs to ADA, a national consortium of over 100 defence laboratories, industrial organisations, and academic institutions with HAL being the principal contractor. The government's "self-reliance" goals for the LCA included the three most sophisticated and challenging systems: the fly-by-wire (FBW) flight control system (FCS), multi-mode pulse-doppler radar, and afterburning turbofan engine.
The IAF's Air Staff Requirements 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 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 locally and which would need to be imported.
Project definition commenced in October 1987 with France's Dassault-Breguet Aviation as consultants. Dassault-Breguet were to assist in the design and systems integration of the aircraft, with 30 top-flight engineers reported to have flown to India to act as technical advisers to IADA, in exchange for $100m / ₹560 crore (equivalent to ₹56 billion or US$790 million in 2019), this phase was completed in September 1988.
LCA programme
A review committee was formed in May 1989, which reported that infrastructure, facilities and technologies in India had advanced sufficiently in most areas and that the project could be undertaken. A two-stage full-scale engineering development (FSED) process was opted for. In 1990, the design was finalised using the "control configured vehicle" concept to define a small tailless delta winged aircraft with relaxed static stability (RSS) for enhanced manoeuvrability.
Phase 1 commenced in April 1993, and focused on "proof of concept" and comprised the design development and testing (DDT) of two technology demonstrator aircraft which were named as TD-1 and TD-2. This would be followed by the production of two prototype vehicles (PV-1 and PV-2); TD-1 finally flew on 4 January 2001. FSED Programme Phase-I was successfully completed in March 2004 and cost ₹2,188 crore.
The relaxed static stability (RSS) was an ambitious requirement. In 1988, Dassault had offered an analogue flight control system (FCS), but the ADA recognised that digital FCSs would supplant it. First flying in 1974, the General Dynamics F-16 was the first production aircraft designed to be slightly aerodynamically unstable to improve manoeuvrability.
In 1992, the LCA National Control Law (CLAW) team was set up by the National Aeronautics Laboratory (now called National Aerospace Laboratories) to develop India's own state of the art fly-by-wire FCS for the Tejas.[36][37] In 1998, Lockheed Martin's involvement was terminated due to a US embargo in response to India's second nuclear tests in May of that year.
Another critical technology is the multi-mode radar (MMR). Initially, the Ericsson/Ferranti PS-05/A I/J-band multi-function radar, also used on Saab's JAS 39 Gripen, was intended to be used. However, after examining other radars in the early 1990s, the Defence Research and Development Organisation (DRDO) became confident that local development was possible. HAL's Hyderabad division and the Electronics and Radar Development Establishment (LRDE) were selected to jointly lead the MMR programme, and work commenced in 1997. The Centre for Airborne Systems (CABS) is responsible for the MMR's test programme. Between 1996 and 1997, CABS converted the surviving HAL/HS-748M Airborne Surveillance Post (ASP) into a testbed for the LCA's avionics and radar.
The NAL's CLAW team completed the integration of the flight control laws 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 January 2001. The automatic flight control system (AFCS) has been praised by all the LCA test pilots. Phase 2 commenced in November 2001, and consisted of the manufacturing of three more prototype vehicles (PV-3, PV-4 and PV-5), leading to the development of the final version that would join the air force and the navy and 8 Limited Series Production (LSP) aircraft, and the establishment of infrastructure for producing 8 aircraft per year. The phase cost ₹3,301.78 crores, and an additional amount of ₹2,475.78 crores was given for induction into Indian Air Force by obtaining IOC and FOC. The total cost for development of Tejas (including PDP, Phase 1 and Phase 2) was ₹7,965.56 crore as of August 2013.
By mid-2002, the MMR had reportedly suffered major delays and cost escalations. By early 2005, only the air-to-air look-up and look-down modes — two basic modes — were confirmed to have been successfully tested. In May 2006, it was revealed that the performance of several modes being tested "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, there was a serious compatibility issue between the radar and the LRDE's advanced signal processor module (SPM). Acquisition of an "off-the-shelf" foreign radar is an interim option being considered.
Of the five critical technologies the ADA identified at the beginning of the programme as required to design and build a new fighter, two have been successful: the development and manufacture of carbon-fibre composite (CFC) structures and skins, and a modern glass cockpit. ADA has a profitable commercial spin-off in its Autolay integrated automated software for designing 3-D laminated composite elements (which has been licensed to both Airbus and Infosys). However, the development of the other three critical technologies (high performance multimode radar, the propulsion and the flight control system) had lagged behind. By 2008, 70% of the LCA's components were being manufactured in India, the dependence on imported components was stated to be progressively reduced over time. However, problems were encountered with the other three key technology initiatives. For example, the intended engine, the GTRE GTX-35VS Kaveri, had to be replaced with an off-the-shelf foreign engine, the General Electric F404.
Kota Harinarayana was the original Programme Director and Chief Designer for the Tejas Programme.
On 26 February 2016, Defence Minister Manohar Parrikar said in the Lok Sabha that the Indian Air Force would accept 3–4 Tejas (IOC version) that year and eventually stand up a total of 8 squadrons within 8 years. He also said, "We are also in the process of approving the second line of manufacturing to the HAL so that they can produce 16 aircraft per year." In October 2015, IAF Air Chief Marshal Arup Raha confirmed that the air force plans to order 123 (six squadrons) of Tejas Mark 1, triple the 40 aircraft it had previously committed to buying. Later it was declared that those 83 additional Tejas ordered would be the upgraded Mark 1A version. On 7 November 2016, Parrikar approved procurement of 83 Tejas for the IAF, at a cost of ₹50,025 crore (US$7 billion), The order for those is expected to be placed by the end of 2019, after the unit price was negotiated between ₹250–₹275 crores (around $40 million) per unit. By March 2020, the HAL, hoped to expand its production capacity to at least a squadron (16+) of aircraft every year to meet delivery timelines. HAL is setting up a second assembly line in collaboration with private industry to increase the production rate of the LCA from current eight to 16; however the March 2020 deadline has been missed.
In 2018, IAF formally committed to buying 324 Tejas aircraft of all versions, if HAL and Aeronautical Development Agency (ADA) could deliver an acceptable quality Tejas Mark 2 in time. The Defence Acquisition Council (DAC) on 18 March 2020 cleared the ₹390 billion ($5.2 billion) procurement deal for 83 Tejas Mk.1A, including 73 single-seat fighters and 10 dual-seat trainers. HAL will now finalise the contract and the proposal will be reviewed by the Cabinet Committee on Security (CCS). According to HAL, the first Tejas Mk.1A will fly by 2022 with serial production starting in 2023. The first squadron of Tejas Mk.1A will be delivered by 2025 and delivery of all 83 aircraft is to be completed before 2029. The Tejas Mk.1A will support the R-77 and Python-5, along with the Astra Mk.1. The IAF also want strong aircraft maintenance package and aircraft panel inter-changeability that can be carried out at squadron level in a minimum amount of time using quick-release fasteners to reduce foreign object damage (FOD). Line-replaceable units (LRU)s are also expected to be pre-positioned.
Prototypes and testing
In March 2005, the IAF placed an order for 20 aircraft, with a similar purchase of another 20 aircraft to follow. All 40 were to be equipped with the F404-GE-IN20 engine. In December 2006, a 14-member "LCA Induction Team" was formed at Bangalore to prepare the Tejas and assist with its introduction into service.[62]
On 25 April 2007, the first Limited Series Production (LSP-1) Tejas performed its maiden flight, achieving a speed of Mach 1.1 (1,347.5 km/h; 837.3 mph). The Tejas completed 1,000 test flights and over 530 hours of flight testing by 22 January 2009. In 2009, a Tejas achieved a speed of over 1,350 kilometres per hour (840 mph) during sea level flight trials at INS Hansa, Goa.
On 16 June 2008 LSP-2 made its first flight followed by the first flight of the trainer variant in November 2009.On 23 April 2010, LSP-3 flew with a hybrid version of the Elta EL/M-2032 multi-mode radar; in June 2010, LSP-4 made its maiden flight in an IAF Initial Operating Clearance (IOC) configuration. By June 2010, the Tejas had completed the second phase of hot weather trials in an IOC configuration with the weapons system and sensors integrated. Sea trials were also carried out. LSP-5 with IOC standard equipment started flight trials on 19 November 2010.
In December 2009, the government authorized a sum of ₹8,000 crores to begin the production of the fighter for the Indian Air Force and Indian Navy. IAF ordered 20 additional Tejas fighters after the defence acquisition council cleared the plan.
In November 2010, it was reported that the Tejas Mk 1 reportedly fell short of the relaxed Air Staff Requirements stipulated for limited series production (LSP) aircraft. The areas that did not meet requirements were power to weight ratio, sustained turning rate, maximum speeds at low altitudes, AoA range, and weapon delivery profiles; the extent of the deficiencies was classified.On 9 March 2012, LSP-7 took to its maiden flight from HAL airport.
In September 2011, weapons tests, including bombing trials, involving four Tejas aircraft — PV3, and LSP 2, 4 and 5 — began at Pokhran range, followed by missile trials at Goa.
On 27 June 2012, three Tejas (LSP 2, 3 and 5) aircraft completed bombing runs in the desert of Rajasthan, using precision laser-guided 1,000 lb bombs and unguided bombs. The Tejas had completed 1,941 flights by July 2012.
In the later half of 2012, the Tejas was grounded for over three months due to a serious safety issue which arose with the introduction of a new pilots' helmet, which protruded above the ejection seat. There was concern that, during an ejection, the helmet would strike the canopy before the canopy was released. Flight tests resumed in November 2012 after the ejection system had been modified. LSP 8 had a successful maiden test flight on 31 March 2013, and the programme had completed 2,418 test flights by 27 November 2013.On 8 November 2014, PV-6 (KH-T2010), a trainer variant, completed its first test flight.
Out of a total of 35 major avionics components and line-replaceable units (LRUs), only three involve foreign systems.These are the multi-function displays (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). Production aircraft are expected to have MFDs from Indian suppliers. A few 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 locally; these sanctions contributed to the prolonged delays suffered by the LCA.
Indian test pilots have praised Tejas' high-speed handling and say the Tejas is the IAF's most "pilot friendly" fighter.Group Captain Samrath Dhankhar of the Indian Air Force, the commanding officer of its 45 Sqn "Flying Daggers" said about Tejas that it responds to pilot inputs in the entire flight envelope very well, with no need to be at certain speeds to get the maximum out of it.
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