Tejas - Light Combat Aircraft avionics

[Stealth Spy]

Use this thread to post details on the LCA's avionics.

I'll set the ball rolling by posting a compilation on its MMR radar :

The Multi Mode Radar or MMR is the primary sensor of the Tejas and will take care of take care of detection, tracking, terrain mapping and delivery of guided weapons.

The MMR is the result of a joint developmental effort of HAL, Hyderabad and LRDE, Bangalore. Drawing upon over 15 years of research, the MMR is India’s first airborne monopulse doppler multimode radar.

The MMR is a mechanically scanned radar with a planar antenna and operates in the X band. The radar is very light in weight and has four major subsystems : the antenna and associated stabilisation system with drive assembly, power amplifier, exciter-receiver, signal/data processing unit.

The antenna is a light weight (less than 5kg), low profile slotted waveguide array and has a diameter of 650mm. It has upto 4 stacks of compact state of the art slotted wave guides which have been designed using CAD software packages and manufactured using computer numerically controlled slot machining and fabrication, dip and vacuum braising. This ensures that the main beam produced is of very high gain and the side lobes are of very low levels. The MMR antenna also features a multi-layered feed network for broad band operation.

Employing a high power output and low/medium/high repetition frequencies, the air to air mode includes – Multi target velocity search, track while scan(TWS), priority tracking and single target track(STT). The MMR achieves a detection range of 100km for typical airborne fighter sized targets (~5 sq.m RCS) .

The track-while-scan feature keeps track of multiple targets (maximum of 10 targets) and also engagement of multiple targets simentaneously . 2 targets can be tracked in the priority track mode and a continuous high quality track of a single target is possible in the STT mode.

The air to ground mode includes – terrain following, terrain/obstacle avoidance, real ground mapping with Doppler beam sharpening. The terrain following and obstacle avoidance modes allow flight down to 100km, facilitating potential flight with cover from enemy ground radar.

The air to sea mode includes sea surface target search and track.

The antenna scan limits are restricted to plus/minus 70 degrees in azimuth and to plus/minus 60 degrees elevation.

Other features of the MMR include integrated Identification of Friend or Foe (IFF) system, and GUARD and BITE channels. Pulse-Doppler gives the MMR look-down shoot-down capability. Ground mapping feature, frequency agility and other ECCM techniques make the radar truly state-of-the-art.

MMR Signal Processor
The heart of MMR is the signal processor, which is built around VLSI-ASICs and i960 processors to meet the functional needs of MMR in different modes of its operation. Its role is to process the radar receiver output, detect and locate targets, create ground maps, and provide contour maps to the pilot when the feature selected.

The post-detection processor resolves range and Doppler ambiguities and forms plots for the subsequent data processor. The special feature of the signal processor is its real-time configurability to adapt to requirements depending on selected mode of operation. Advanced signal processing algorithms and tracking filters ensure good performance against high speed and extensively maneuvering targets.

Other generic functions of the signal processor include: Detection of airborne and surface targets by employing LPRF/MPRF/HPRF waveforms depending on the selected mode, Platform motion compensation, MTI and Doppler filtering, CFAR detection, Range-Doppler ambiguity selection, Scan conversion, Display of target and ground maps on the Multi Function Displays (MFD’s), real-time configurability and Online diagnostics to identify faulty processor modes.

MMR Pulse Coupled Cavity TWT – MPC 4068
The MPC 4068 is an inverted slot mode coupled cavity (inter digital) TWT with a non-intercepting griddled gun, PPM focussing, single stage depressed collector and liquid cooling that has been developed by the Microwave Tube Research and Development Centre (MTRDC). It has a high gain of 38dB, high efficiency, and a high spectral purity even when under heavy vibration. It is of small size with dimensions of 370x160x120mm and weighs 6.5kg. Electrical connections are made through flying leads and cooling is done with liquid Coolanol flowing at 15 lpm. The peak output of the TWT is 6.5kW and has a duty cycle of 10%.

Sources : (Added later)

Official ADA released information
Force Magazine article
Vayu Magazine article
Spacetransport article collection
MTRDC's periodic journal
DRDO's periodic journal

Cheers,
Stealth Spy

 

[Pit]

Re: Tejas - Light Combat Aircraft avioincs

Stealth Spy,

In this forum we encourage the members to post the sources of their info wathever is possible. This is for further reference and study of the subject. May you please post the sources you used for this recollection?

Thanks for your input.

 

[JCage]

Some nice details about the entire development process.

http://pib.nic.in/release/release.asp?relid=18294

Meeting the computational challenge: AGNI programme

Let me share with you the development of hypersonic missile system AGNI missile, a long range missile. When AGNI re-enters in the atmosphere, it experiences a high enthalpy with the temperature of 4000oK all around the heat shield and the nose cone. We had then designed and developed the structure using a material based on Carbon-Carbon which can withstand this high temperature. The problem we faced was to simulate the external aerodynamic flow in the subsonic, supersonic and hypersonic speed regime. In India, we can externally simulate subsonic, sonic and supersonic flow. But in 1989, we did not have a hypersonic wind tunnel facility and also for AGNI class of missiles, developed countries did not give their wind tunnel facility to be used because of the technology denial. Hence, in that situation, we had to resolve the problem only through CFD (Computational Fluid Dynamics). CFD was then a new field. In India, CFD groups were in formation stage at various institutions. Prof SR Deshpande, IISc (Indian Institute of Science), Bangalore and Dr. KP Singh from ADA and their teams were pioneering in this area. About 20 members were in CFD team from various organizations. When CFD problem was formulated initially, the computational time in an IBM computer needed 240 hours. At that time, we neither had so many computers in India nor the adequate time. Prof Deshpande and the DRDL team evolved what is called "kinetic energy split methodology". The problem which needed from very large computer time was solved with 1/10th of the computer time using elegant methods by suitably segmenting the problem. Also, it triggered the necessity of design and development of super computers in the country. This led to the birth of super computers. Today, India has PACE+256, a parallel computing facility with one Terra Flop capacity for advanced CFD solutions. The evolution of Grid Computing which has got tremendous potential in connecting multiple locations and utilizing the computing power from different institutions is in progress in India. I am giving you this example so that when you face such challenges in your institutions you can find innovative methods by which you can progress the development tasks instead of getting defeated due to the non-availability of certain facility. Now I would like to narrate the methodology adopted by LCA team for progressing research when technological sanction was imposed by USA after 1998 event.

Technology denial and management Challenge: LCA

In the year 1992, LCA team decided to go for Digital-Fly-by-Wire Control System (FCS) for the Combat Aircraft as it is an unstable aircraft. At that time, the country did not have the experience in developing FCS. The only two countries who had the experience were France and US. The French company (Dassault System) had expertise in Hybrid systems whereas our need was an all Digital-Fly-by-Wire. Hence, it was thought appropriate to have a US partner who has the capability in design, development and integration of FCS on fighter aircraft. There were three candidates, LMCS, USA; Lear Astronics and Bendix. Finally, we chose LMCS for the contract since they had the experience in designing FCS for F-16 Aircraft. Joint Team for design and development of the FCS was formed with ADE (DRDO Lab) and LMCS. The work share between Indian team and LMCS team was identified. Evolution of the SRS (Software Requirement Specification) was the joint effort. The prototype flight control computer was to be done by ADE. Total system integration of FCS was the joint responsibility. Flight certification was to be provided by LMCS, USA.

The $40 million contract was progressing to meet the required schedule. Then as you all are aware, India became a nuclear weapon state in May 1998. As soon as this event occurred the American Government imposed technological and economic sanction. Due to the sanction, LMCS, USA broke the contract and retained all the Indian equipment, software and the technical information which were in their premises.

This was definitely a challenging mission for the Indian team. There was a crisis. Immediately, we had an urgent task team meeting with Directors and their team from ADA, NAL, ADE, CAIR, HAL, National Flight Test Center, Prof I.G. Sharma of IISc a renowned control system specialist, Prof T.K. Ghoshal of Jadavpur University, a digital control system expert and guidance and control specialists from DRDL and ISRO. We had a full day discussion on the methodology required to be followed through which we can successfully complete the development of digital fly by wire system and fly the LCA. The team, after prolonged deliberations gave a structured method by which the development can be completed and the system can be certified for flight trials. They also mentioned that they will support the programme in whatever capacity they have to work with the ADE and ADA teams.

Based on the recommendations of the specialists we immediately strengthened the ADE software team with additional ten experienced software engineers from ADA. ADA was given the responsibility of verification and validation of software. Integrated flight control system review committee was constituted with Director (ADE) as Chairman and PGD (ADA) as Co-chairman to support development and resolve all the conflicts arising between Control Law Team, Iron Bird, Software, Hardware and simulation. This team met once in a week and brought out all the issues arising in different work centers and solutions were found. In addition, Iron Bird (A test platform of Flight Control System) review team was formed with Project Director Flight Control System as Chairman with members from HAL, ADA, ADE, certification agency (CEMILAC) and Test Pilots from National Flight Test Center as Members. This team also met every week and resolved all the problems arising in the development and Test on Iron Bird. Any deviation in the PERT Chart or any difficulty, team members could directly bring the problem for discussion when I met them every alternate Saturday of the month. We also introduced participation of certification agency (CEMILAC) and inspection agency (CRI) in all these reviews. The aim was to see that any problem in any system is brought into focus at the earliest so that the solution can be found. In addition, we made it a point to have a special agenda in the monthly technical committee meeting on the development of integrated flight control system wherein Director (ADE), Director (NAL), Director (National Flight Test Center), General Manager (HAL) presented the progress and problems. The confidence building took place by intensifying the tests. For example informal Iron Bird test was carried out over thousand hours and the formal Iron Bird test was conducted over hundred and fifty hours. Similarly, Pilot flew the LCA simulator for more than two thousand hours. Thus, what we missed from the foreign partner, we compensated by enhancing the design, critical design review and increasing the test time to ensure safe man rated design of the integrated flight control system. This gave the confidence to the user, the Air Force.

 

[Austin]

FORCE

Reality Check
By Prasun K. Sengupta

It was in August 1998 that Dr APJ Abdul Kalam as scientific adviser to the defence minister, had announced in Bangalore that the ‘Tejas' Light Combat Aircraft (LCA), post-Pokhran-2 sanctions by the US notwithstanding, would be inducted into service by the Indian Air Force (IAF) in 2003. Now that is likely to happen only after 2012. Eleven years after it was rolled out (on 21 November 1995 ) and since its maiden flight on 4 January 2001, the single-engined, multi-role Tejas has only proved its reliable airworthiness characteristics throughout its envisaged flight envelope. Despite incurring an expenditure of Rs56 billion (USD1.2 billion) over the past 23 years, it still is a long way off from becoming the versatile fourth-generation combat aircraft that it was originally envisaged to be. It is now estimated that the entire R&D effort for Tejas will cost Rs100 billion (USD2.26 billion) by 2012. The Defence Research and Development Organisation's (DRDO) Bangalore-based Aeronautical Development Agency (ADA), which was established in 1984 with the sole purpose of coordinating the R&D effort for Tejas, now expects the Tejas to achieve initial operational capability only by 2012 and that too if it is powered by an imported turbofan, since the indigenous GTX-35VS Kaveri turbofan will not be ready for series production until 2012.

The LCA's project definition phase commenced in October 1987 and was completed in September 1988 with the help of Dassault Aviation, while the detailed design phase was concluded in 1990. To fast-track prototype development, ADA had decided in 1990 that full-scale engineering development (FSED) would proceed in two phases — design, development, and test phase, costing Rs30 billion (USD666 million) and commencing in 1990 and concluding by 1994, followed by the engineering-cum-production development phase, costing Rs33 billion (USD704 million) under which three more prototypes (PV-3 as the baseline production variant, PV-4 as the tandem-seat operational conversion trainer aircraft, and PV-5 as the definitive production variant) and a structural fatigue test specimen, would be built (by 1998) and powered by General Electric's (GE) F404F2J3 turbofans. This well laid-out R&D roadmap was, however, totally disrupted by the severe financial crunch faced by India between 1991 and 1996, and by the post-Pokhran-2 sanctions between May 1998 and late 2001. Consequently, phase 1 of FSED was concluded only on 31 March 2004 by using two Technology Demonstrators (TD-1 and TD-2, with the latter taking to the skies on 6 June 2002 ), and one prototype (PV-1 that first flew on 25 November 2003, and a structural test specimen.

Tejas-LCA-PV-2


Phase 2 of FSED commenced in November 2001 and is currently using PV-1 and PV-2 (that flew on 1 December 2005 ), with the PV-3 due to make its maiden flight at press time and PVs 4 and 5 now undergoing final assembly. In addition, PVs 2, 3, 4 and 5 are all being equipped with an integrated digital avionics suite (IDAS) that will include the all-glass cockpit and related hands-on-throttle-and-stick controls, integrated electronic warfare and communications suites, mission and stores management systems, and a yet-to-be-selected monopulse multi-mode radar that will likely be the EL/M-2052 active phased-array model from the ELTA Electronics Division of Israel Aircraft Industries (IAI), since the indigenous X-band mono pulse-Doppler radar (with a mechanical scanning antenna) remains highly overweight, is still undergoing laboratory development at the Hyderabad-based facility of the MoD-owned Hindustan Aeronautics Ltd (HAL), and is highly unlikely to meet the qualitative requirements of the IAF. ADA has also obtained IAI's technical expertise for finalising the IDAS' weight-budgeted architecture and progressively integrating the IDAS with the LCA's digital, quadruplex fly-by-wire flight control system, for validating the fully-armed LCA's flight control logic, and for phase 1 of the weapons qualification stage that will include the 23mm twin-barrel internal cannon, RAFAEL's Litening-2 laser designation/target acquisition pod, 500lb and 1,000lb laser-guided bombs, plus Vympel's R-73E and R-77 air combat missiles.

ADA and HAL signed a MoU in 2001 for eight limited series production (LSP) variants of the Tejas at a cost of Rs5 billion. The production order, however, was placed in June 2002, and production go-ahead was given in March 2003. Despite this, HAL has not yet commissioned its assembly/production lines for the eight LSP aircraft, the first of which are required by early next year. ADA considers this unpardonable since it has been continuously and simultaneously providing the aircraft's designs via the product-line management system to HAL's Aircraft Research and Design Centre, and also because funds for the assembly/production lines were made available three years ago. Consequently, all eight LSP aircraft are expected to be airborne by 2012, with the first two units being used from mid-2009 for full flight qualification-cum-weapons qualification purposes. In April 2003, the MoD released to ADA the sum of Rs10 billion (USD210 million) for developing two prototypes — single-seat NP-2 and tandem-seat NP-1 — of the LCA's aircraft carrier-launched variants. Their detailed designs had been frozen in early 1999, followed by production go-ahead being given in mid-2002 and release of production funding in early 2003. Both aircraft will commence their carrier launch-and-recovery flight trials in late 2009 from INS Vikramaditya, and are expected to enter service by 2012. Earlier this year, the MoD released Rs20 billion (USD450 million) for HAL to begin series production of the first 20 LCAs, which along with the eight LSP aircraft and NP-1 and NP-2 prototypes, will be powered by F404-GE-IN20 turbofans, which have been developed specifically for the Tejas by GE, following a USD105 contract awarded by ADA to GE in February 2004 to develop and deliver 17 such engines by this December, and another 20 by early 2008.

Beyond this, the future of the Tejas remains a question mark, especially since no follow-on orders for the turbofans to power the remaining 160 LCAs planned for induction have been placed so far, not even with HAL, whose Koraput-based Engine Division was selected more than a decade ago to series-produce the Kaveri turbofan. The Kaveri is widely acknowledged to be the Achilles heel of the LCA's series production phase. Under development by the DRDO's Bangalore-based Gas Turbine Research Establishment (GTRE) since 1986, its R&D effort has thus far incurred a cost of Rs28.39 billion (USD640 million). Requests for Proposals (RFP) were floated by the GTRE in July 2005 for a undertaking a ‘peer review' of the entire project and suggesting financially viable ways of achieving successful R&D closure over a 15-month period and undertaking joint production of the Kaveri with foreign engine manufacturers. Four entities — GE, Pratt & Whitney, SNECMA Moteurs and NPO Saturn — submitted their proposals within two months. Yet, it was only i n February this year that the DRDO awarded a contract to SNECMA Moteurs of France for technical assistance in working out the Kaveri's engineering development problems, especially the fabrication technologies required for bulk production of the Kaveri's single-crystal turbine blades, which the MoD's Hyderabad-based Mishra Dhatu Nigam Ltd (MIDHANI) has been unable to master thus far. Consequently, all six Kaveri prototypes built thus far incorporate directionally solidified turbine blades, which the IAF finds totally unacceptable.

 

[JCage]

Reality Check
By Prasun K. Sengupta

It was in August 1998 that Dr APJ Abdul Kalam as scientific adviser to the defence minister, had announced in Bangalore that the ‘Tejas' Light Combat Aircraft (LCA), post-Pokhran-2 sanctions by the US notwithstanding, would be inducted into service by the Indian Air Force (IAF) in 2003. Now that is likely to happen only after 2012. Eleven years after it was rolled out (on 21 November 1995 ) and since its maiden flight on 4 January 2001, the single-engined, multi-role Tejas has only proved its reliable airworthiness characteristics throughout its envisaged flight envelope. Despite incurring an expenditure of Rs56 billion (USD1.2 billion) over the past 23 years, it still is a long way off from becoming the versatile fourth-generation combat aircraft that it was originally envisaged to be. It is now estimated that the entire R&D effort for Tejas will cost Rs100 billion (USD2.26 billion) by 2012. The Defence Research and Development Organisation's (DRDO) Bangalore-based Aeronautical Development Agency (ADA), which was established in 1984 with the sole purpose of coordinating the R&D effort for Tejas, now expects the Tejas to achieve initial operational capability only by 2012 and that too if it is powered by an imported turbofan, since the indigenous GTX-35VS Kaveri turbofan will not be ready for series production until 2012.

The LCA's project definition phase commenced in October 1987 and was completed in September 1988 with the help of Dassault Aviation, while the detailed design phase was concluded in 1990. To fast-track prototype development, ADA had decided in 1990 that full-scale engineering development (FSED) would proceed in two phases — design, development, and test phase, costing Rs30 billion (USD666 million) and commencing in 1990 and concluding by 1994, followed by the engineering-cum-production development phase, costing Rs33 billion (USD704 million) under which three more prototypes (PV-3 as the baseline production variant, PV-4 as the tandem-seat operational conversion trainer aircraft, and PV-5 as the definitive production variant) and a structural fatigue test specimen, would be built (by 1998) and powered by General Electric's (GE) F404F2J3 turbofans. This well laid-out R&D roadmap was, however, totally disrupted by the severe financial crunch faced by India between 1991 and 1996, and by the post-Pokhran-2 sanctions between May 1998 and late 2001. Consequently, phase 1 of FSED was concluded only on 31 March 2004 by using two Technology Demonstrators (TD-1 and TD-2, with the latter taking to the skies on 6 June 2002 ), and one prototype (PV-1 that first flew on 25 November 2003, and a structural test specimen.

Tejas-LCA-PV-2


Phase 2 of FSED commenced in November 2001 and is currently using PV-1 and PV-2 (that flew on 1 December 2005 ), with the PV-3 due to make its maiden flight at press time and PVs 4 and 5 now undergoing final assembly. In addition, PVs 2, 3, 4 and 5 are all being equipped with an integrated digital avionics suite (IDAS) that will include the all-glass cockpit and related hands-on-throttle-and-stick controls, integrated electronic warfare and communications suites, mission and stores management systems, and a yet-to-be-selected monopulse multi-mode radar that will likely be the EL/M-2052 active phased-array model from the ELTA Electronics Division of Israel Aircraft Industries (IAI), since the indigenous X-band mono pulse-Doppler radar (with a mechanical scanning antenna) remains highly overweight, is still undergoing laboratory development at the Hyderabad-based facility of the MoD-owned Hindustan Aeronautics Ltd (HAL), and is highly unlikely to meet the qualitative requirements of the IAF. ADA has also obtained IAI's technical expertise for finalising the IDAS' weight-budgeted architecture and progressively integrating the IDAS with the LCA's digital, quadruplex fly-by-wire flight control system, for validating the fully-armed LCA's flight control logic, and for phase 1 of the weapons qualification stage that will include the 23mm twin-barrel internal cannon, RAFAEL's Litening-2 laser designation/target acquisition pod, 500lb and 1,000lb laser-guided bombs, plus Vympel's R-73E and R-77 air combat missiles.

ADA and HAL signed a MoU in 2001 for eight limited series production (LSP) variants of the Tejas at a cost of Rs5 billion. The production order, however, was placed in June 2002, and production go-ahead was given in March 2003. Despite this, HAL has not yet commissioned its assembly/production lines for the eight LSP aircraft, the first of which are required by early next year. ADA considers this unpardonable since it has been continuously and simultaneously providing the aircraft's designs via the product-line management system to HAL's Aircraft Research and Design Centre, and also because funds for the assembly/production lines were made available three years ago. Consequently, all eight LSP aircraft are expected to be airborne by 2012, with the first two units being used from mid-2009 for full flight qualification-cum-weapons qualification purposes. In April 2003, the MoD released to ADA the sum of Rs10 billion (USD210 million) for developing two prototypes — single-seat NP-2 and tandem-seat NP-1 — of the LCA's aircraft carrier-launched variants. Their detailed designs had been frozen in early 1999, followed by production go-ahead being given in mid-2002 and release of production funding in early 2003. Both aircraft will commence their carrier launch-and-recovery flight trials in late 2009 from INS Vikramaditya, and are expected to enter service by 2012. Earlier this year, the MoD released Rs20 billion (USD450 million) for HAL to begin series production of the first 20 LCAs, which along with the eight LSP aircraft and NP-1 and NP-2 prototypes, will be powered by F404-GE-IN20 turbofans, which have been developed specifically for the Tejas by GE, following a USD105 contract awarded by ADA to GE in February 2004 to develop and deliver 17 such engines by this December, and another 20 by early 2008.

There are severa mistakes made in Mr Senguptas impressive wishlist:

For instance:

The IDAS...In addition, PVs 2, 3, 4 and 5 are all being equipped with an integrated digital avionics suite (IDAS) that will include the all-glass cockpit and related hands-on-throttle-and-stick controls, integrated electronic warfare and communications suites, mission and stores management systems, and a yet-to-be-selected monopulse multi-mode radar that will likely be the EL/M-2052 active phased-array model



The LCAs SMS is already flying iirc in a manner of speaking, on the Jag upgrades. The all glass cockpit will use Elta MFDs but will be driven by the OAC (ADA) which does the work of mission computing, display processing and video switching, the RWR will be Tarang series, the communications suite is INCOM with standby UHF, the Mission Preparal and retrieval unit is already being used on the MiG-21 Bison, HOTAS has been there on LCA from day 1.

Only place where he makes some sense is use of Israeli jammer+MAWS+LWS, ie Mayavi and the 2052 radar which could probably come in.

Even here, the MMR can have a X Band array presumably replace it in future, once the current MMR is debugged and made to work.

Beyond this, the future of the Tejas remains a question mark, especially since no follow-on orders for the turbofans to power the remaining 160 LCAs planned for induction have been placed so far, not even with HAL, whose Koraput-based Engine Division was selected more than a decade ago to series-produce the Kaveri turbofan. The Kaveri is widely acknowledged to be the Achilles heel of the LCA's series production phase. Under development by the DRDO's Bangalore-based Gas Turbine Research Establishment (GTRE) since 1986, its R&D effort has thus far incurred a cost of Rs28.39 billion (USD640 million). Requests for Proposals (RFP) were floated by the GTRE in July 2005 for a undertaking a ‘peer review' of the entire project and suggesting financially viable ways of achieving successful R&D closure over a 15-month period and undertaking joint production of the Kaveri with foreign engine manufacturers. Four entities — GE, Pratt & Whitney, SNECMA Moteurs and NPO Saturn — submitted their proposals within two months. Yet, it was only i n February this year that the DRDO awarded a contract to SNECMA Moteurs of France for technical assistance in working out the Kaveri's engineering development problems, especially the fabrication technologies required for bulk production of the Kaveri's single-crystal turbine blades, which the MoD's Hyderabad-based Mishra Dhatu Nigam Ltd (MIDHANI) has been unable to master thus far. Consequently, all six Kaveri prototypes built thus far incorporate directionally solidified turbine blades, which the IAF finds totally unacceptable.

If India wishes, it can order as many Ge404 IN20s as it wants to, for LCA production. But the IAF wants a local engine, hence the focus on Kaveri. Sengupta is as usual, making up stuff when he says that the single crystal blades are an issue (as if the IAF cares what will be used, as long as the engine is productionr ready and works!)- the issue was of vibration issues in certain thrust criteria, as well as manufacturing assistance for certain components. IOW Snecma is coming in for these issues.

 

[JCage]

Excellent article on the LCA, which I had totally forgotten about. An IAF person places the challenges, and extremely ambitious aims into perspective. When one hears "delay, delay", it also bears reckoning how ambitious (and practically impossible), the original schedule itself is!

BHARAT RAKSHAK MONITOR - Volume 3(5) March-April 2001

http://www.bharat-rakshak.com/MONITOR/ISSUE3-5/wollen.html

The Light Combat Aircraft Story
Air Marshal MSD Wollen (Retd)


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, 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, he selected proven engine' from abroad, could not be procured; the project fell through. HAL's design and development capability started to de-cline. 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 inflight simulation tests of flight control software took place in July 1996 at Calspan USA on an F-16D VISTA (variable inflight stability aircraft); 33 test flight 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 hack; 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 bee 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! 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 manoeuvrability.

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; 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 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/contributing to the project. In the main, they are devoted and tireless in their efforts to success-fully complete the project. They need support (not blind sup-port) 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 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 targetting 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 he setbacks in the flight development phase. All major engineering projects suffer them e.g. 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 he lost, leading to questions/debate. Therefore, let the recent transparency in tile program continue, even intensify; let it he honest, 2010 is not far, for a first' program of this magnitude and complexity.


The author, Air Alarshal M.S.D. Wollen (Retd) was chairman Hindustan Aeronautics Limited from September 1984 to March 1988. This aricle is reproduced with permission of the author. It first appeared in. Indian Aviation, Opening Show report, Aero India 2001.