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Feature - The Light Combat Aircraft Story by Air Marshal MSD Wollen (Retd)
The author, Air Marshal M.S.D. Wollen (Retd) was the chairman of Hindustan Aeronautics Limited from September 1984 to March 1988. He entered the Indian Air Force in 1947 and was awarded the Param Vishisht Seva Medal (PVSM) for his exemplary role in the 1971 Indo-Pak War. It was during his tenure at HAL that the design and development of the Advanced Light Helicopter and Light Combat Aircraft (LCA) was undertaken. He is considered an authority on LCA, and MIGs in particular. Air Marshal Wollen has authored several papers on aviation and here he talks about Tejas and the reason why it is so important.
This story is incomplete.
With the maiden, 20-minute flight of the first Technology Demonstrator of the Light Combat Aircraft on January 4, 2001, one could say it was halfway through. Even at this point of time, it is of enormous interest to nations in the far corners of the world. India has two priorities One, improve the quality of life of a third of its population. Two, keep inviolate its borders, shores and skies. The latter requires military might.
The geo- politics of the region (South Asia and surrounds) is of such a complexity that, despite good intentions of all, major conflicts have erupted; border skirmishes and cross- border terror-ism continue. In fact, right from Day 1 (August 15, 1947) India has faced a military threat; because of this, there is a compulsion to achieve self-reliance in design, development and production of weapon systems e.g. the LCA. It may be noted that some Asian countries, with great economic wealth and technical know why/know how, do not have such a compulsion. Further, success of the LCA program is a must for continuation and enhancement of India's aircraft industry. For these reasons, 33 R&D establishments; 60 major industries and 11 academic institutions participate in the program. Unfortunately, there has been a great deal of hype by the Defence Research and Development Organisation (DRDO) as to its capabilities, contemporariness and when it will enter service. This has led to, although not unwarranted, cynicism.
Background Information
An important recommendation of the Aeronautics Committee, which was accepted by Government in 1969, was that Hindustan Aeronautics Ltd (HAL) should design and develop an advanced technology fighter aircraft around a proven engine. Based on IAF 'air staff target' papers, HAL finally completed design studies for a Tactical Air support Aircraft in 1975 and it appeared that HAL would, after a lapse of twenty years, get down to developing a fighter. However, the selected 'proven engine' from abroad, could not be procured and the project fell through. HAL's design and development capability started to decline. Meanwhile, The IAF's requirement for an air superiority fighter (primary role) with air support/interdiction capability (secondary role) in the tactical battle area, continued.
The DRDO obtained feasibility studies from three leading aircraft companies (British, French and German). Use was made of these studies in presenting a case to Government for design and development of an LCA. In an unusual step, a Society was set up to over-see the LCA development program. At its apex is a 15-member General Body, whose president is the Defence Minister. The next rung is a 10-member Governing Body, whose Chairman is the SA to the Defence Minister and Secretary DRDO. The third rung is a 10-member Technical Committee, headed by the DG Aeronautical Development Agency (ADA); the latter post has been vacant ever since the first DG resigned in 1986. ADA manages the development program while HAL is the principal partner. The initial projection for completion of the program was totally erroneous and is largely attributable to lack of knowledge and experience. Projections were: first flight in 1990; production to commence in 1994.
Delay in commencement of Project Definition (PD) gave ADA time to marshal national resources (80 work centers spread over the country); to construct buildings, recruit personnel and create infra-structure; and to get a clearer perspective of the advanced technologies that could be indigenously developed and those that would need to be imported. The IAF's Air Staff Requirement, finalized in October 1985 is the base document for development. Requirements of flight performance, systems performance, reliability, maintainability criteria, stores carnage, etc. are spelt out. Concessions or a higher standard of requirements have to be mutually agreed upon by the IAF (customer) and ADA (constructor). Having a Society and Committees is, perhaps, the quickest way to bring about agreement.
The Program
Project definition (PD) commenced in October 1987 and was completed in September I988. The consultant, chosen from four contenders, was Dassault Aviation, France. Engineers, connected with design and development of aircraft know how vital it is to get the 'definition' correct. From this flows detail de-sign, construction and eventually maintenance costs.
After examining the PD documents, the IAF felt that the risks were too high (likely shortfalls in performance, inordinate delay, Cost over-run, price escalations) to proceed further. A Review Committee was formed in May 1989. Experts from outside the aviation industry were included. The general view was that infrastructure, facilities and technology had advanced in most areas to undertake the project. As a precaution, Full Scale Engineering Development would proceed in two phases. Phase 1: design, construction and flight test of two Technology Demonstrator aircraft (TDI & 2); construction of a Structural Test Specimen; construction of two Prototype Vehicles (PVI &2); creation of infrastructure and test facilities. Phase 2: construction of three more PV '5, the last PV5, being a trainer; construction of a Fatigue Test Specimen; creation of facilities at various work centres. Cost of Phase I - Rs.2188 crores, of Phase II - Rs. 2,340 crores. Phase I commenced in 1990. However, due to a financial crunch, sanction was accorded in April 1993 and was marked by an upsurge in work. The critical path in this program has been the design, fabrication and testing of its fly-by-wire flight control system FCS). An electronic FCS is a must for an aircraft with relaxed static stability.
The FCS also provides the pilot 'care free handling'; flight limits cannot be exceeded, which at lower speeds on aircraft like the MiG-23/27 or Jaguar, results in the loss of the aircraft. The Aeronautical Development Establishment (ADE) is the nodal agency for development of the FCS. One reason for delay of the first flight could have been the unexpectedly large effort required for coding control laws into the FCS software, which were then checked out on Minibird and Ironbird test rigs at ADE and HAL, respectively. The control laws were developed with the aid of real time simulators at ADE and BAe, UK. As a point of interest, a second series of in-flight simulation tests of flight control software took place in July 1996 at Calspan USA on an F-16D VISTA (variable in-flight stability aircraft); 33 test flights were carried out. Another reason for delay was the sanction imposed after Pokhran II in May 1999. Scientists working at Lockheed Martin, USA were sent back; equipment, software and documents were impounded. Herculean efforts brought the FCS software to a standard where the FCS performed flawlessly over 50 hours of testing on TD 1 by pilots, resulting in the aircraft being cleared for flight in early 2001.
Space constraints prevent any meaningful description of materials, technology, facilities, processes developed for execution of the project. Military aviation enthusiasts may read a monograph on Aeronautical Technology that has attained maturity through DRDO efforts; much of this technology finds application in the LCA project. The monograph was brought out at Aero India 1998. The LCA is tailless with a double-sweep delta wing. Its wing span is 8.2 m, length 13.2 m, height 4.4 m. TOW clean 8.500 kg, MTOW 12500kg. It will be super-sonic at all altitudes, max speed of M 1.5 at the tropopause. Specific excess power and g-over load data has not been published. Maximum sustained rate of turn will be 17 deg per sec and maximum attainable 30 deg per sec. Funds have been sanctioned for a Naval LCA. PD and studies in critical technology areas have commenced. The aircraft will be powered by a Kaveri engine (more information follows) and is to operate from the Indian Navy's Air Defence Ship, under construction. Launch speed over a 12 deg ramp is 100 kts; recovery speed during a no flare deck landing, using arrester gear, is 120 kts. Take off mass 13 tonne, recovery mass 10 tonne. Most stringent requirements are that the airframe will be modified: nose droop to provide improved view during landing approach; wing leading edge vortexes (LEVCON) to increase lift during approach and strengthened undercarriage. Nose wheel steering will be powered for deck maneuverability.
During early flight development, the TD aircraft will be powered by a single GE F404 F2J3 engine (7,250 kg reheat thrust). The indigenous Kaveri engine, under development by the Gas Turbine Research Establishment (GTRE) is slated for installation in a PV aircraft. Over 7,000 hours of ground testing of the core engine (Kabini) and four prototype Kaveri engines, together with flights in a Tu-16 test-bed aircraft would have been completed. Engine components have been produced by several manufacturing units, including HAL, where the exclusive Cellular Manufacturing Facility (CNC machining) was established in November 1988. A concurrent engineering approach has been followed to provide engines early in the LCA's flight development. Salient engine features include the 3 stage fan; 6 stage HP compressor with variable geometry IGV, I and II stators; annular combustion chamber; cooled single stage HP and LP turbines; modulated after-burner; fully variable, convergent-divergent nozzle; length 3490 mm; max diameter 910 mm; dry thrust 52 kN; reheat thrust 81 kN; thrust weight ratio 7.8. The 'Achilles heel; in the successful development of the LCA, in the opinion of this author, is the Kaveri engine.
Points of view
In the late eighties India's aircraft Industry was not as advanced as Sweden's; and yet India follows a more arduous design/development route for its LCA, compared to Sweden for its JAS-39 Gripen. The Gripen embodied a far higher percentage of foreign, off-the-shelf technology, including its RM-12 engine (improved GE F404). France (Dassault Aviation) built and exhaustively flew a demonstrator aircraft (Rafale-A) before embarking on construction of Rafale prototypes. Over 2,000 flights were completed by September 1994 when first Flight of a production Rafale was still 20 months away. At that point of time, Dassault Aviation had built or flown 93 prototypes, of which at least fifteen went into production after sixteen years elapsed from 'first-metal-cut' of the Rafale demonstrator to entry into service. Current plans for the LCA is ten years. And what of India's past record? Just a hand-ful of trainer aircraft designed and productionised. The story is similar for the Typhoon (earlier Eurofighter 2000). It was seventeen years from 'first-metal-cut' (EAP) to squadron entry in 2000. One more timeframe needs to be noted. It took Gripen six and a half years from first flight (prototype) to entry into squadron. For the LCA, four and a half years is the target! The quantum of test flying hours required to attain Initial Operational Clearance (IOC) is about 2000 hours; an impossible task in four and a half years. Concurrent production will shorten service entry time, but this will not enable the present target to be reached.
The LCA remains a high-risk project. All too often glitches occur in development of a fly-by-wire FCS. The Typhoon is an example; this, despite vast experimental work for over a decade by leading aircraft manufacturers in the UK and Germany (Jaguar, F-104, EAP). Engine development is the most complex of all activities. There are sure to be problems during flight development of the Kaveri, GTRE's first engine. Teething problems after service entry will occur; and major reliability improvements will be required in the first decade of its exploitation. Engines of the Russian fleet of fighters operated by the IAF (MiG-21 BIS, MiG-23BN/27M MiG-29) have this in-service history. Proceeding from this, four points emerge:
(a) India has its best designers, engineers, scientists, academicians working on and contributing to the project. They are devoted and tireless in their efforts to success-fully complete the project. They need support (not blind support) of the polity, defence services and bureaucrats. Public support will follow, provided there is honest transparency;
(b) Costs of the project will escalate. (Checks and balance are necessary, but let there be no inordinate delays, as have occurred in the past;
(c) The future of the aircraft industry, military and civil, depends on success of the LCA (and ALH, Saras, HJT-36) project; and,
(d) It is unlikely that the LCA will attain initial operational clearance (IOC) before 2010.When it is achieved, it will be an industrial success of magnificent proportion, and is sure to receive the acclaim it deserves.
A few words on the final operational clearance (FOC). The entire avionics and weapon systems are con-figured around three 1553 B data bus. Mission oriented computation/flight management is through a 32 hit computer. Information: from sensors (e.g. multi-mode radar, IRST, radar/laser/missile launch-warning receivers); from the inertial navigation System with embedded GPS; from targeting pod (FLIR, laser designator) are presented to the pilot on a head-up-display and head-down-displays. A helmet mounted target designator steers radar and missile seekers for early target acquisition (during a 'close-in' air-to-air engagement with a Vympel R-73 missile, currently the best dog-fight' missile in the world). Laser guided bombs and TV guided missiles, require a pilot to initially 'zero-in' the laser designator or missile-mounted TV camera, on the ground target. Considerable engineering effort and expertise is necessary to achieve avionics-weapon integration and to prove the integration by live trials. Success here means FOC. Depending on what is stated in the (updated) ASR, it could take two years and around 1,500 hours of flight testing to move from IOC to FOC.
There will be setbacks in the flight development phase. All major engineering projects suffer them. For instance, India's first two SLVs failed disastrously. The Prime Minister was present at the first launch at Sriharikota; so was this author. Disappointment was everywhere but no recrimination; only determination to get it right. Loss of a demonstrator aircraft or prototype could take place; lives could be lost, leading to questions/debate. Therefore, let the recent transparency in the program continue, even intensify; let it be honest, 2010 is not far, for a first' program of this magnitude and complexity.
This article is reproduced with the permission of the author. It first appeared in Indian Aviation, Opening Show report, Aero India 2001.
Tejas - Feature - The Light Combat Aircraft Story by Air Marshal MSD Wollen (Retd)
