India's TEJAS fighter has come a long way, its new iteration is the Twin-Engine Deck Based Fighter

by Air Marshal Philip Rajkumar (Retd)

It was only a couple of weeks ago that the Cabinet Committee on Security headed by Prime Minister Narendra Modi gave the go ahead for the manufacture of 83 homegrown fighter jets, the Light Combat Aircraft (TEJAS MK-1A) better known as Tejas. While this move meant a big boost for India's aviation industry, it was also a project that was many decades in the making. In his book, The Tejas Story: The Light Combat Aircraft Project, retired air marshal Philip Rajkumar chronicles the sweat, toil and courage of the officers and pilots involved at the various developmental stages of India's LCA program. The Indian Air Force pilot headed Tejas' flight test program for nearly a decade, beginning in 1994 and took prototypes to the skies to check for cracks and faults in the design. The story that comes to life through his book is that of his team of pilots and of the LCA program itself, how it was commissioned, the challenges in the development phase and the pressure of realising the dream of domestically developing a fighter plane.

The excerpt that follows takes off from the first flight of the prototype to morph into the beginning of the TEJAS story, the role of aeronautical engineers and scientists in the project's initial stages and how several Indian research and defence organisations came together to work on designing the fighter plane.

The military precision with which the events of the day of the first flight unfolded and the flawless performance of the prototype, gave many people the erroneous impression that what had been achieved was easy and inconsequential. The Raksha Mantri, George Fernandes, told us much later that on the day preceding the first flight, a foreign aerospace company had written to him warning him of catastrophic consequences, if he permitted the first flight to take place. Their view was that the FCS software had not been developed with adequate rigour and had not been validated properly. It is therefore very important for me to set the record straight and give the reader an insight into the challenges overcome by Team TEJAS, while developing the aircraft.

The TEJAS story actually began in the late 1970s. Air Chief Marshal IH Latif was the CAS from 1978 to 1981. He was unhappy with the in-service performance of the HAL upgraded Gnat, the Ajeet fighter. The aircraft had severe limitations of payload, range and serviceability and did not fit into the planned re-equipment of the IAF fighter fleet. He was also aware of the need to phase out some of the earlier versions of the Mig-21 in the mid-1990s. He therefore asked HAL to design a relatively low-cost replacement for the Ajeet and the MiG-21.

In 1980 India was able to successfully put a 40 kg satellite into low earth orbit and join a very select club of nations with that capability. The Indian Space Research Organization (ISRO) and its engineers received well-deserved kudos in the national and international media. Unfortunately, the aeronautical community had nothing remotely as significant as the Rohini to show for their existence since the 1940s. When some leading aeronautical personalities approached Prime Minister Indira Gandhi in the early 1980s with a request to be given a chance to prove their design capabilities, she took the bold step of asking them to design a state-of-the-art fighter for the IAF.

The planners at Air Headquarters got to work and issued an Air Staff Target (AST) for a cost-effective replacement for the Ajeet and Mig-21. The aeronautical scientists and engineers did not agree with that approach, and wanted to utilize the opportunity to bridge the technology gap that had opened up between India and the advanced countries of the world since the Marut (HF-24) program of the 1960s. They wanted the aircraft to have four crucial new technologies which were the fly-by-wire Flight Control System (FCS), a glass cockpit (round dial analogue instruments being replaced by multi-function displays controlled by a mission computer), composite materials in the airframe and micro-processor controlled general systems. They also decided to develop the jet engine to power the TEJAS as well as a Multi Mode Radar (MMR) which would be the primary sensor on board the aircraft. The seeds for protracted program delays and cost overruns were sown by these decisions. The IAF not wanting to sound overly pessimistic went along with these ideas, and took the first step of issuing an AST for a multi-role fighter while expressing serious reservations about the development schedule. An AST is a document which contains a preliminary set of operational requirements drawn up by the IAF for discussion with the design agency. During these discussions, designers tell the planning staff at Air HQ whether the operational targets given in the AST can be met with existing technologies available in the country, or whether there would be a need to develop new technologies indigenously, or source them from abroad.

HAL realized they had no experience of working with any of the technologies which had to be incorporated into the new aircraft to meet operational requirement targets set out in the AST. They were very under-confident of developing an aircraft by the mid-1990s to meet IAF re-equipment plans. They rightly assessed that the program would require the harnessing of national capabilities across a spectrum of technologies and considerable investment of time and resources towards project management. They felt they were not equal to the task and agreed to the creation of a separate program management agency.

In 1985 Rajiv Gandhi had become the Prime Minister at the young age of 45 years. An equally young Scientific Adviser to the Raksha Mantri (SA to RM), Dr VS Arunachalam, had a grand dream of making DRDO a world class R&D organization. An immediate rapport was established between these two decision makers. Dr Arunachalam became a special favourite of the Prime Minister, but Dr Arunachalam was a metallurgist and not an aeronautical engineer. He quite naturally assumed that anything could be accomplished given the necessary political support, resources, leadership and dedication of the workforce.

Dr Arunachalam was able to prevail upon the GOI to create a Society under the Ministry of Defence called the Aeronautical Development Agency (ADA) to act as the program management agency for the LCA project. ADA was to be headed by a Director General who would report to the SA to RM. The principal partner in the program was to be HAL along with other public sector agencies, the private sector and academic institutions. Dr SR Valluri, former Director of the National Aerospace Laboratories, was appointed the first Director General of ADA in mid-1985. Dr Valluri was a very renowned aeronautical scientist and commanded much respect in professional circles. He chose Raj Mahindra, former MD of the HAL Design Bureau to be the chief designer of the TEJAS. They went about putting together a team of designers drawn from ISRO, HAL, NAL and the IAF. A search for a foreign partner was also started, and discussions were held with Dassault Aviation of France, Messerschmitt, Bolkow & Blohm (MBB) of Germany, Dornier of Germany and British Aerospace (now BAE Systems) of the UK. After prolonged discussions at Air HQ, the Ministry of Defence, HAL and the Defence Research and Development Organization (DRDO) an Air Staff Requirement (ASR) for a multi-role fighter was issued by Air HQ in late-1985.

Around this time in late-1985, serious differences emerged between Dr Arunachalam and Dr Valluri over the choice of the chief designer for the project. Dr Arunachalam felt Raj Mahindra was too old to be at the helm of a long gestation project like the design and development of a modern fighter aircraft and wanted a younger man. Dr Valluri refused to relent and resigned from his post. Dr Arunachalam assumed the mantle of DG ADA as well and started looking around for someone in his forties to run the program. The choice was very limited as there was no one in India who had any experience in managing such a complex undertaking. Finally at the end of 1986, 43-year old Dr Kota Harinarayana who was Director, Aeronautical Development Establishment (ADE) was appointed the Program Director (LCA), and was for all practical purposes the head of ADA.

Government sanction was received in 1986 to build five prototypes at an estimated cost of about Rs 575 crore. Choosing a foreign collaborator proved difficult, and hectic negotiations were conducted all through 1986. Finally, Dassault Aviation of France was chosen to provide the necessary inputs for the Project Definition Phase (PDP). About 500 HAL Design Bureau engineers were deputed to ADA for the PDP. A dozen aeronautical engineers from Dassault came to Bangalore in July 1987 and got down to work. As all this activity was going on, a debate began about technology choices. The most crucial technology and expertise Indian engineers were interested in, was the fly-by-wire FCS. There was a school of thought which said American FCS technology was the best in the world and the TEJAS should have nothing less. Another equally strident point of view, which was supported by the IAF, was that the USA was an unreliable source of technology, given its penchant to impose sanctions on countries that did not toe its line of thinking. European sources of technology though not quite up to US standards were far more reliable and therefore India should not go to the USA for the FCS for the TEJAS. While this debate raged, certain political developments took place which improved Indo-US relations.

Soon after he became the Prime Minister, Rajiv Gandhi went on an official visit to the USA and met President Ronald Reagan for the first time. The leaders of the world’s two largest democracies immediately established a good bond between them. When Rajiv Gandhi asked Reagan for help for the TEJAS program his request was readily agreed to. The United States Air Force (USAF) was the agency designated to provide help to the Indian DRDO to develop the fly-by-wire FCS. The USAF in turn detailed Wright Laboratories, Dayton, Ohio, to do the needful and the DRDO laboratory chosen to absorb the technology transfer was the Aeronautical Development Establishment (ADE), a DRDO laboratory at Bangalore. The USA also offered to provide GE F-404 jet engines to power the prototypes. This offer was accepted by ADA as everyone knew that the indigenous engine, the Kaveri, would take time to develop, test and certify. In 1987 ADA bought 11 GE F-404 engines at a cost of nearly US$ 11 million. By the end of 1988 the PDP was completed and the report was circulated to various agencies including Air HQ. The report landed up on the table of Air Commodore S. Krishnaswamy (Kitcha, later CAS), Director Air Staff Requirements. Kitcha was an experienced fighter pilot and a graduate of the Empire Test Pilots School, Boscombe Down, UK.

At that time, in early 1988, he happened to be one of the very few people at Air HQ who understood the nuances of technology choices. He wrote a report on the PDP document, which was very sceptical about ADA’s ability to design a state of the art fighter with a host of new technologies, which were being introduced into an aircraft for the first time in the country. He felt, quite rightly, that the time frame projected for design, development including flight testing and introduction into service was far too ambitious. He also said that without foreign help it would be very risky to develop the flyby-wire system, the glass cockpit, the composite airframe and the micro-processor controlled general systems. Due cognizance was taken of this report by the decision makers at Air HQ. The IAF recommended that a confidence and competence building route of proving the four crucial technologies, by flying two Technology Demonstrator aircraft through a limited flight test program, be followed before embarking on full scale engineering development of prototypes.

Dassault Aviation was very keen to partner ADA in the TEJAS program and offered the three digital channels with an analogue fourth channel fly-by-wire technology which they had successfully developed for the Rafale fighter. The FCS computer would be a hybrid digi-ana computer having three digital processors with three independent channels and one hard wired analogue channel. In the 1980s confidence in digital technology was not very high, and the French thought it was a good idea to have an analogue channel as a back-up in case of any problems with the digital channels. They said they would go for a quadruplex digital fly-by-wire FCS when they had gained more experience with the digi-ana hybrid FCS.

Unfortunately, their offer was spurned in favour of the quadruplex digital fly-by-wire technology offered by Martin Marietta Control Systems (MMCS), later Lockheed Martin and now BAE Systems of the USA. The FCS computer would be fully digital having four digital processors with four independent channels. The Americans were very confident about the reliability of digital technology and there was no doubt that at that time it was cutting edge technology.

Since they would have no control over the development of a system as crucial as the FCS, Dassault Aviation walked out of the program, a decision which I am sure both parties regret to this day. With an experienced aircraft house like Dassault as a partner ADA/HAL may well have been able to develop the aircraft, and have it in service by the end of the 1990s. In my view, the decision to accept the US offer of quadruplex digital fly-by-wire technology and go it alone with only consultancy agreements with various foreign firms added a decade or more to the program. This decision, I suspect, was taken because the thrust was to acquire the latest technology and build self-reliance through indigenization rather than on delivery of an operational fighter in a reasonable time frame to meet IAF modernization plans. It was a classic case of the ‘best’ being the enemy of the ‘good’. Operational requirements should drive technology choices and not the other way around.

At the end of 1989 Rajiv Gandhi lost the general election, and Dr Arunachalam had to establish new equations with the VP Singh government. In August 1990, Saddam Hussein of Iraq invaded Kuwait, oil prices sky rocketed and the country’s foreign exchange reserves depleted rapidly. The GOI was unable to decide to go ahead with the program. Two whole years were lost before the program could be put back on track.