Tejas Mk1’s Future Prospects

It has cost India Rs140.47 billion—spent over a period of 29 years—to acquire the core technological and industrial competencies required for producing a home-grown medium multi-role combat aircraft (M-MRCA) like the ‘Tejas’. In the process a total of 40 laboratories owned by the Defence Research & Development Organisation (DRDO), 25 academic institutions, 300 public-/private-sector companies, and a combined design/engineering team made up of 600 personnel had to be roped in to realise the national dream of developing a fourth-generation M-MRCA for both the Indian Air Force (IAF) and Indian Navy (IN). The entire R & D programme was divided into 1,200 packages, while for flight certification purposes, the aircraft was categorised into 17 major systems with 346 line-replaceable units (LRU) and 33 software-embedded systems. Additionally, in order to bridge the technological and infrastructure gaps of two generations, critical ground-based facilities like the National Flight Testing Centre (NFTC) were built over the past decade.

Yet, despite all these, the ‘Tejas’—designed by the DRDO’s Bengaluru-based Aeronautical Development Agency (ADA)-- still incorporates a substantial amount of systems, sub-systems and components of foreign origin, notable the turbofan and key components of the navigation-and-attack system and the airborne multi-mode radar (this being the Israel Aerospace Industries-built EL/M-2032 for the ‘Tejas’ Mk1). Principal foreign vendors associated with the ‘Tejas’ Mk1 and its Mk2 variant include Intertechnique SA and IN-LHC ZODIAC of France; US-based GE Aero Engines, Hamilton Sunstrand, EATON Aerospace, MOOG, and Goodrich Aerospace; UK-based CHELTON Avionics, Penny + Giles, and Martin Baker (supplier of Mk 16LG zero-zero ejection seats); Italy’s Secondo Mona; and Germany’s Cassidian and Faure Herman. UK-based Cobham is in discussions with IAF HQ about retrofitting a retractable refuelling probe. Indian companies involved include Hindustan Aeronautics Ltd (HAL), Tata's Advanced Materials Ltd (TAML), Data Patterns Pvt Ltd, Government Tool Room and Training Centre (GT & TC), and SLN Technologies Pvt Ltd.

The programme for indigenously developing the ‘Tejas’ light combat aircraft (LCA) was initiated in August 1983, when India’s Ministry of Defence (MoD) sanctioned an interim development cost of Rs5.6 billion for carrying out the project definition phase (PDP). After completing the PDP, the report was submitted to the MoD and a proposal to build seven LCA prototypes was made. The MoD consequently split the programme into the Technical Development Phase and Operational Vehicle Development Phase. The Full-Scale Engineering Development Programme Phase-I (LCA FSED Phase-I) was sanctioned in April 1993 at a cost of Rs21.88 billion (including the interim sanction of Rs5.6 billion given in 1983). The scope of FSED Phase-I was to demonstrate the core technology competencies in areas such as airframe design and development, digital fly-by-wire flight control system and the navigation-and-attack system, so that a decision could be taken to build operational prototypes at a later stage. Under FSED Phase-1, two ‘technology demonstrator’ aircraft were built without any adjustments for inflation or foreign exchange appreciation, even though the US$ had shot up from Rs26 to Rs47 during that period. The forex component of Rs8.73 billion should have been adjusted to Rs16.42 billion. LCA FSED Phase-I was completed on March 31, 2004. While Phase-I was in progress, the MoD decided to concurrently go ahead with the building of operational prototypes. The scope of FSED Phase-2 was to build five IAF-specific prototypes, including a tandem-seat operational conversion trainer, and two naval prototypes (a single-seater and a tandem-seater) and also to build the industrial infrastructure required for producing eight LCAs per year and build eight limited series production (LSP) aircraft. The MoD sanctioned FSED Phase-2 of the programme at a total cost of Rs 33.02 billion on November 20, 2001. Phase-2 was consequently split into two phases, namely, initial operational clearance (IOC) and final operational clearance (FOC). The design and performance parameters of ‘Tejas Mk1’ LCA’s operational version were finalised in 2004 to meet the Indian Air Force’s (IAF) requirements and overcome obsolescence, since the original design was of early 1990s vintage). This in turn contributed to additional time and revised cost schedules for Phase-II.  The governing body of ADA in its 41^st meeting held on November 22, 2007 made a detailed review of the R & D programme and deliberated on achievements vis-à-vis objectives of the FSED Phase-2 programme, and recommended the extension of FSED Phase-2’s likely date of completion till December 31, 2012 (IOC by December 2010 and FOC by December 2012), with GE-F404-IN20 turbofans being used to power the Tejas Mk1 LCA, and to develop and productionise the aircraft’s Mk2 variant, and also recommended the constitution of a cost revision committee (CRC) to assess additional requirements for R & D funds.

The need for extending the PDC for FSED Phase-2 was due to:

·  Complexity of the systems design and very high safety standards, which required extensive testing to ensure flight safety.

·  Incorporation of configuration changes (for example the Vympel R-60 close-combat air-to-air missile was replaced by the R-73E, which required design modifications) to keep the aircraft contemporary.

·  Non-availability of the indigenous Kaveri turbofan, due to which design changes were carried out to accommodate the GE-F404-IN20.

·  Change in the development strategy of the airborne multi-mode radar (which was then being developed by Hindustan Aeronautics Ltd) and associated changes on the aircraft.

·  Major development activities concerning the mission management avionics suite and defensive aids suite had to be undertaken in order to make aircraft contemporary, which took time but yielded results (for example, the development of an obsolescence-free open architecture avionics system).

·  US sanctions imposed in May 1998 also led to delays in importing certain items and developing alternate equipment, since vendor identification and development to production-cycle took time.

The need for revised FSED Phase-2 funds sanction was mainly due to:

·  Neutralising the effect of inflation/delivery point cost against the sanctioned level at 2001 and the increase in manpower cost of HAL.

·   To meet the programme management expenditure due to extended timeline till December 2012.

·   Maintain and operate 10-15 prototype vehicles and LSP aircraft for four years up to 2012.

·  To maintain and upgrade the design, development and test facilities up to 2012.

·  To complete the activities, which were not costed in the original estimates.

The CRC, after careful consideration of the projections made and taking into account the increase in the cost of raw materials, manpower, additional activities to complete the IOC and FOC, maintenance of industrial facilities and expanded scope of the R & D programme, recommended an additional fund of Rs24.75 billion for completing FSED Phase-2 activities for the ‘Tejas’ Mk1 with a projected date of completion (PDC) of December 2012, Rs24.32 billion for developing the IAF-specific ‘Tejas’ Mk2 with an alternate, more powerful F414-GE-400 turbofan (under the LCA FSED Phase-3 programme) and Rs3.95 billion for its technology development programme (all totaling at Rs53.02 billion), plus Rs19.21 billion for developing trhe Navy-specific Tejas Mk2. The recommendations of the CRC were accepted by the MoD and in November 2009, sanction was accorded for continuing full-scale engineering development of the ‘Tejas’ Mk2 till December 2018. FSED Phase-3 has since been launched concurrently with the on-going FSED Phase-2 programme. Thus far, ADA has spent Rs60.51 billion on developing the IAF-specific ‘Tejas’, out of the Rs79.65 billion allocated thus far. Additionally, Rs7.46 billion (of the sanctioned Rs17.29 billion) has been spent on developing the the naval, aircraft carrier-based variant of the ‘Tejas’. Both the IAF and Indian Navy are respectively funding 40% of the Tejas Mk2’s R & D expenditure, with ADA picking up the rest of the tab. Thus, by 2012, the total development cost for the IAF-specific and Navy-specific ‘Tejas’ variants will total Rs96.90 billion, another Rs43.53 billion will be spent on developing the Tejas Mk2, bringing the total cost to Rs140.47 billion.

Presently, the IAF is gearing up to form the first ‘Tejas’ Mk1 squadron--No45 ‘Flying Daggers’ Sqn—which will initially be first raised in Bengaluru before relocating to Sulur in Coimbatore, Tamil Nadu in 2013. Two LSP aircraft—LSP-7 and LSP-8—will be used for flight evaluations (for achieving full operational capability, or FOC) by the IAF’s Bengaluru-based Aircraft & Systems Testing Establishment (ASTE) starting June last year and led by the IAF’s Wg Cdr Paranjal Singh (experimental test pilot) and Wg Cdr Manish Kumar (flight-test engineer). Two other LSP aircraft—LSP-4 and LSP-5—built to comply with the IAF’s specifications for the ‘Tejas’ Mk1—have been located at the NFTC for realising the flight certification/weapons qualification objectives. For achieving FOC, LSPs 7 and 8 will both be subjected to a tedious certification-cum-flight envelope extension process that will involve field-tests for each and every component and validation of their performance parameters, such as drop-tank ejection, stores integration and ejection, airframe flutter, pitot tube performance, airborne fire-control radar’s modes of operation, and robustness of the digital, quadruplex fly-by-wire flight control system, navigation-and-attack system, stores management system, and the defensive aids suite. Also explored will be the aircraft’s ability to sustain increased g-force levels, higher angles of attack, and improved instantaneous and sustained turn rates. Logically, ADA should have been able to achieve all these objectives prior to handing over the first two ‘Tejas’ Mk1s (LSP-2 and the tandem-seat PV-5) to the IAF on January 10 last year. However, ADA’s inability to complete the flight certification process on time, coupled with the ‘Tejas’ Mk1’s (unforeseen) increased takeoff weight has resulted in the IAF now shouldering the burden of completing the aircraft’s flight certification/weapons qualification processes. The issue of overweight has also resulted in the aircraft’s earlier GE-built F404F2J3 turbofans (11 of which were acquired for powering the TDs and PVs) now being superceded by the 85kN-thrust F404-GE-IN20 turbofans on board the IAF-specific LSPs and the 40 production-standard ‘Tejas’ Mk1s on order, and the consequent redesigning of the production-standard ‘Tejas’ Mk1’s fuselage to accommodate the engine, as well as incorporate larger air-intakes for catering to increased air-flow requirements.

The first two production-standard aircraft--SP-1 and SP-2--will be handed over to IAF by July, with SP-3 and SP-4 following by the year’s end. The first 20 of 40 SP models are now being assembled by HAL in four custom-built hangars that can presently handle an annual production run of eight aircraft. The airframes of these aircraft will incorporate 13 major composites-built structures fabricated by TAML, which was awarded the contract after the state-owned National Aerospace Laboratory (NAL) expressed its failure to deliver the structures on time. Structures being produced by TAML for each aircraft include a rudder assembly, fin assembly, 60 carbon-fibre reinforced (CFC) wing spars, 38 wing fuselage fairing skins, 20 wing fuselage fairing blocks, 41 CFC centre fuselage components, two forward undercarriage doors and two aft undercarriage doors. Earlier, HAL on February 16 last year ordered an additional 24 F404-GE-IN20s worth US$100 million to power the first ‘Tejas’ Mk1 operational squadron. This follows an initial February 2004 purchase of 17 F404-GE-IN20s engines worth $105 million to power a limited series of LSP and production-standard aircraft, and two naval prototypes. The F404-IN-20 has to date completed more than 350 hours of accelerated mission testing, which is the equivalent of 1,000 hours of flight operation. Last year, HAL and ADA commenced weight reduction work on the flightworthy LSPs under a two-pronged approach. Firstly, the removal of on-board telemetry instrumentation has reduced the ‘Tejas’ Mk1 LSP-7’s weight by 400kg. Secondly, by re-engineering several of the cockpit-mounted AMLCDs and related sub-systems, another 300kg in weight savings will be achieved on LSP-8. These in turn will result in the ‘Tejas’ Mk1 having a total weight of 10.5 tonnes with full internal fuel tanks and two R-73E within-visual-range air combat missiles. The maximum projected weapons payload (distributed among seven pylons) is 3.5 tonnes, while the maximum takeoff weight is targetted by the IAF at 13 tonnes.

Systems integration work for the ‘Tejas’ Mk1 has been an area of both enormous challenge and missed opportunities. For instance, the indigenous X-band multi-mode pulse-Doppler radar (with a mechanical scanning antenna) remains highly overweight, and has still not been fully developed by HAL. Secondly, the IAF HQ mandated six years ago that the original Honeywell-built H-4524L ring laser gyro-based inertial navigation system be replaced by the SIGMA-95N (built by SAFRAN of France), which was followed in 2008 by the selection of ELTA Systems of Israel’s EL/M-2032 multi-mode pulse-Doppler radar for the ‘Tejas’ Mk1. All this involved a total redesign of the aircraft’s fire-control and navigation-and-attack systems, and writing new software algorithms for the DRDO-developed open-architecture mission computer. Consequently, it was only on April 23, 2010 that LSP-3, equipped with the EL/M-2032, took to the skies. It was only after this milestone that work on full-scale weaponisation of the ‘Tejas’ Mk1 got underway. For air superiority missions, the ‘Tejas’ Mk1 will use the Vympel-built R-73E and the 50km-range Derby beyond-visual-range air combat missile, the latter coming from  Israel’s missile RAFAEL Advanced Defence Systems Ltd. The IN’s ‘Tejas’ Mk1 variants, on the other hand, will use a combination of RAFAEL-built Derby and Python-5 air combat missiles. However, both the IAF and IN have decided to use RAFAEL’s Litening-3 laser designator pod for all-weather air-to-ground precision strikes, and Elbit Systems of Israel’s TARGO helmet-mounted display/cueing system.—Prasun K. Sengupta