An Update on the HAL LCA (Tejas) - July 2002
- Category: Current Aircraft Articles
- Last Updated: Wednesday, 25 November 2009 03:34
- Written by Gp Capt Kapil Bhargava
- Hits: 19832
More than one and half years down the line from its first flight, India’s prestigious aeronautical project, the Light Combat Aircraft (LCA) is progressing slowly. Meanwhile the Government of India and presumably the Air Force have demonstrated their commitment to the project by approving the manufacture of eight limited series production aircraft, in addition to the prototypes previously sanctioned.
To an extent the slow rate of development of the LCA was anticipated especially in view of US sanctions imposed on India (and Pakistan) after conducting nuclear tests in May 1998. The declared date of LCA’s first flight slipped steadily for ten years till the Technology Demonstrator 1 (TD-1) flew on January 4, 2001. TD-1 completed its first modestly planned batch of test flights in a flawless manner in June 2001. It was then taken in for upgradation of software of its Fly-By-Wire (FBW) and other systems. This is yet to be completed and as a result no LCA was flown for more than one year.
Twelve flights were carried out on TD-1 in six months by June 2, 2001. It was flown up to an indicated airspeed of 610 km per hour and a height of 8 km., 2g turns (60° bank) and rolls (restricted rate) were executed. Two test pilots reported that the aircraft handled better than the Mirage 2000 during close formation, flare out for landing and touchdown. In the first phase of flight testing, accuracy of static and dynamic pressures (at pitot heads) was determined and flight control laws of its four-channel digital flight control system (FCS) were verified with a gradual expansion of the flight envelope. The inherently unstable aircraft with its centre of gravity (cg) aft of centre of pressure was flown with limitations in the control law of FCS. Fuel feed line from the aircraft’s front tank was blocked, ensuring that the cg remained relatively forward though the aircraft was still inherently unstable. It was fitted with a GE 404 F2J3 engine (83.2 KN reheat thrust, of US origin). It had several indigenously designed and fabricated systems installed such as a 'brake by wire system'. In fact the aircraft is a first in Asia for integrating utility systems with the mission computer.
The first flight of TD-2 was forecast for Oct 2001. After many taxi trials, it finally got airborne on June 6 2002 under the control of National Flight Test Centre (NFTC) test pilot Wg Cdr Tarun Banerjee. The flight was carried out with an indigenous Head Up Display (HUD) from a Council of Scientific and Industrial Research (CSIR). Laboratory, the Central Scientific Instruments Organisation (CSEIO), and a new integrated communications system from HAL. This phase of flight testing on TD-2 may consist of 20 or 30 flights but flying any LCA beyond Mach 1 is some way off. The projected dates for flying the first production version of LCA and its induction into the Indian Air Force (IAF) between 2005 and 2007 seem over-optimistic. The Kaveri engine is getting ready according to DRDO but there are grave doubts about the claims for it. The Prototype Variant 1 (PV-1) is undergoing system integration tests. PV-2 is expected (by Aeronautical Development Agency - ADA) to be ready by end-2002 and PV-3 by 2003.
According to the NFTC, in charge of flight testing of the LCA, at least 200 successful flights are necessary to declare the end of the Technology Demonstration phase. About 1100 flights will be required for Initial Operational Clearance, probably by 2010. Obviously, urgent steps are essential to ensure the success of the project.
Immediately after the first flight of TD-2, Dr Kota Harinarayana announced that he was giving up being the Programme Director of ADA and was keen to teach budding aeronautical designers. He has now been appointed Vice Chancellor of a University in Hyderabad. Air Marshal Philip Rajkumar (Retd), who was Director NFTC and was waiting in the wings, took over as Director ADA on June 7 2002. At the same time, Mr M.B. Verma assumed charge as Programme Director of the LCA project.
|The LCA TD-2 KH-2002 made its first flight on 6 June 2002. (Left) Wg. Cdr. Tarun Banerjee (Right) being the test pilot on this flight.|
In the development of any new aircraft, some systems invariably give trouble. Modifications or redesign are usually necessary to correct problems that crop up. These are what may have caused delays in getting TD-2 airborne. Break up of the designer-pilot-developer team can only harm a project. This may now happen to the LCA.
|KAVERI ENGINE TO DELAY LCA
The Kaveri engine programme has been slipping regularly. Some core engine stages have been tested in the high altitude facility in Russia. The whole engine to be tested in this facility prior to flight tests has been delayed and may not be available till late 2002 or early in 2003.
A mock up of the engine was sent to Russia only for installation studies. Russia uses a Tu-16 for engines like the Kaveri by installing them on a cradle in the bomb bay. For take off and landing, the engine on the cradle is held retracted in the bomb bay. This allows the aircraft to operate in a clean condition.
The cradle is lowered for testing the engine at the required altitude and speed. An engineer with some controls and instrumentation operates the engine. However, data produced during the test is recorded for analysis on the ground. The pilot in charge of the Tu-16 has over-riding authority to throttle back or cut the engine on test.
With a third engine (of Kaveri class) the Tu-16 can reach its airframe limit of March 0.85 in level flight. This will be the speed to which Kaveri engine tests will be limited on the Tu-16.
The delays in the Kaveri programme are a serious hazard for the LCA itself. It may become essential for India to use the GE 404 engine as an interim solution. While USA has announced a relaxation of many sanctions against India, Congressional approval is still awaited for some critical. Perhaps the most India could expect immediately is to purchase more GE F-404 engines and control actuators. The Air Force may resist inducting LCAs powered by these engines into service, as the aircraft will not meet its operational mission requirements.
The departure of the two test pilots who had flown TD-1 for its first phase of testing had already taken place. Wg Cdr Rajiv Kothiyal who did the maiden flight of the LCA and followed it up with five more reverted to the IAF. He may have by now asked for premature retirement from the IAF1, but not for joining NFTC. Wg Cdr Ragunath Nambiar did the next six flights of the TD-1. He also rejoined normal IAF duty. Wg Cdr Tarun Banerjee, who took over the task of flying TD-2 quite some time ago, finally got his very first experience of an LCA. He had flown chase for most flights of TD-1 and is now the project pilot at NFTC, perhaps also only for a limited period. Two new test pilots were posted in to NFTC. After studying the aircraft and the history of its development so far, Sqn Ldr Sunith Krishna has now done several flights on TD-2. The second pilot should also undertake some test flights soon2. Continuity of the pilot in charge of a major project is often vital to the successful development of an aircraft type. Apparently, this cannot be ensured for the LCA’s development.
The relationship between pilot's demand and aircraft’s response as implemented by the FCS software according to a pre-programmed schedule is called a gain. It is necessary to define this for each combination of altitude and Mach Number taking inputs from more than thirty parameters involved. So far, on TD-1 only two fixed gains were used – one with undercarriage down and the other with it retracted. This limited the expansion of its flight envelope.
There are other constraints, which may slow down the project. On TD-2, flights with perhaps six gains were planned. The software for this was not quite ready; the earlier fixed two gains control law may have been incorporated for its first flight. This implies that there will be little or no expansion of the aircraft’s flight envelope. On TD-1 the next phase of flight tests of about 35 hours with a complete suite of gains is planned to extend the flight envelope initially to Mach 1.1 and +4g
Even though TD-2 flew with an indigenous HUD and HAL’s integrated communications system (both claimed to be improved over imported equipment) many of the forty or so systems, originally expected mostly from the USA, are still being developed within the country. This has surely resulted in further delays. DRDO needs to concede that it cannot deliver all the promised systems in time to meet IAF’s aspirations for the LCA. Hindustan Aeronautics Limited (HAL) and IAF buy a large quantity of systems and components to meet their requirements. This needs to be done for the LCA as well. Of particular importance are engines, radar, electronic warfare and smart weapon systems, and even flight control actuators. With the recent improvement in Indo-US relations, some vital components for the LCA are now likely to be delivered by US corporations. If IOC is not obtained by (say) 2010, IAF is quite likely to lose interest in the project. As it is, it has ensured adequacy of its inventory by buying and agreeing to licensed production of Su-30 MKI aircraft. A number of Mirage 2000, with upgraded software and weapons systems is also very likely to be acquired. In short, with abundant caution, the IAF is already moving towards being able to cope with delays in the induction of the LCA into squadron service.
The DRDO perhaps does not agree with these views. Comparing the LCA programme status with other aircraft types in its category, Dr. Harinarayana had once said that the Eurofighter (Typhoon), which was originally scheduled to fly in 1990, took off only in 1994. Similarly, work on the F-22 Raptor started in the US in 1980, but the aircraft flew for the first time in 1997, after a gap of 17 years. US sanctions that were faced by India did not affect both these programmes yet they took a long time to come up. "It is, therefore, not unusual for high technology programmes to take time," he observed. Dr. Harinarayana said that a large number of parameters, which were being monitored in the first phase of testing, would now be eliminated. He had expected to complete the LCA task in 30 per cent less time, given the success of flight testing so far. Regarding the cost of the LCA, he said, it would be cheaper than its rivals. The LCA aircraft would work out to US $17 million each while the Typhoon costs between US $ 70 to 80 million and the F-22 is priced at about US $ 105 million. Nearly 4,000 fighters, presently in operation around the world, would need to be replaced over the next 15 years and the LCA was an excellent option. However, with the departure of Dr. Harinarayana from the programme, some of his unrealistic promises and predictions may not be fulfilled by his successors.
According to an ex-Chairman, HAL is flourishing with licensed production of Su-30 MKI, joint venture R&D of a 100-seater aircraft and a tactical transport version, development and later production of an intermediate jet trainer, series production of the Advanced Light Helicopter, a light attack helicopter, upgradation of MiG-21 Bis, MiG-27, Jaguar and soon production of the twin engine Saras airliner. Delay in productionising the LCA may be a setback for the aircraft industry but would not sound its death knell. However, failure of the project would be a serious blow to India’s aspirations in aeronautical R&D.
This article first appeared in Air Forces Monthly July 2002 issue. The first flight of the TD-2 just happened after the article was submitted for AFM. Since then, this piece has been updated by the author and is reproduced here exclusively.
1. It has been reported in the Times of India on September 21st that Wg Cdr Rajiv Kothiyal put in his papers for premature retirement .
2. The second pilot at NFTC who flew the TD-2 is Group Captain Rakesh Bhaduria, who flew the TD-2's 14th flight on September 19, 2002.
Copyright © Group Captain Kapil Bhargava (Retd). All rights reserved.