Given the Features and Functionality of the Tejas, We Feel the Weight is Reasonable’
Director ADA, P.S. Subramanyam
What is the current status of the LCA programme?
We have developed 2 technology demonstrators TD-1 and TD-2; we have the four prototypes PV-1, PV-2, PV-3 and PV-4. The Limited Series Production aircraft ranging from LSP-1 to LSP-4 are all flying. TD-1, TD-2 and PV-1 have now become outdated and are used for ground testing or testing of equipment that needs to be developed for the Tejas. All the aircraft from PV-2 onwards are participating in the flying test campaign. LSP-5 is currently the final ‘Standard of Preparation’ that we will deliver to the Indian Air Force (IAF) and this aircraft is expected to fly this month. LSP-6 and LSP-7 will follow and have been earmarked for the user evaluation by pilots belonging to the Aircraft Systems and Testing Establishment (ASTE).
Both the IAF and the Indian Navy have committed some money for the Tejas Mk-2 which will be equipped with a higher performing engine. We now have a concurrent programme to develop the Tejas Mk-2 version for the IAF and the Indian Navy. The PV-5 which is a trainer version of the Tejas’ is flying and another aircraft PV-6 is expected to fly by the end of this year. The maiden flight of the Tejas Mk-2 is expected to take place in December 2014 and production will begin in December 2016.
What is the current order book for the Tejas and what orders can be expected in the future?
Based on the progress observed by the IAF an order for 20 ‘Tejas’ fighters was placed by the IAF in 2006. Further developments in the LCA programme have resulted in order for another 20 aircraft. There exists a requirement on paper for 100 fighters (five squadrons) for the IAF and a 50 for the Indian Navy, which has been put up to the government of India. The technology growth in engines has been so rapid that is has been very difficult to keep pace with the technology. As a result, the Kaveri engine which we began with in the early Nineties is now unable to match the performance requirements demanded by the user. We are confident that the Tejas equipped with the alternate engine will provide the IAF with a fighter which offers contemporary performance over a decade of service.
What is the configuration of the LSP versions and what changes will Mk-2 versions entail?
Equipment-fit LSP-wise is in the final standard of preparation for the IAF. All the sensors, communication equipment and weapons required for the current Initial Operational Clearance (IOC) are present. Also since we were designing a fighter of this class for the first time, we were very conservative in the design. Especially when it came to structural strength characteristics and this has lead to an increase in weight. Weight optimisation will be undertaken for the Tejas Mk-2 variant to reduce its weight. The Mk-2 version will also have better Centre of Gravity (CG) management and maintainability features. Within the programme feasibility, we will be revamping the cockpit electronics to bring it more up to date with technologies that will be prevalent around 2016. There will be advanced electronics, improved cockpit displays and interfaces which will remain contemporary even in the 2020’s.
The Tejas Mk-2 will feature an alternate engine which will offer a performance increase of about 10 per cent. The engine change for Mk-2 will result in the rear fuselage being changed and intakes having to be redesigned. All these structural changes will also reflect in drawing changes and parts fabrication. The digital Fly by Wire (FBW) Flight Control System (FCS) will not change. We do not see much impact when it comes to hydraulics, electronics and undercarriage, etc. With regards to the developmental programme this will not be a major impact.
What is the update on the LCA Naval version?
The ‘Power On’ for the Navy version has to take place where we test all the functions; this will be followed by four to six weeks of exhaustive testing. If we are able to demonstrate the naval variant at the Shore Based Test Facility (SBTF) in Goa, then the navy may consider orders for the Mk-1 variant of Tejas itself, to fill the gap for light fighters to operate off its careers. We also expect the navy to order around 2 squadrons of the Mk-2 variant. Initial funding of about Rs 900 crore was obtained for the Naval variant in 2003, as we went along there were many challenges and we found that a major portion of the structure had to be strengthened, nose droop was required, extra control surfaces and the flight control system of Naval variant differs from the IAF variant because of the low speed landing requirements of the LCA Navy. In hindsight, it would have been easier to design the naval variant first and then quickly move onto the air force variant and not the other way around. Our initial estimates on the amount of work required on the Naval variant were not quite accurate and the programme gave us some surprises.
What is being done to address concerns that the LCA is overweight?
When you consider the amount of features and functionality given in the Tejas, we feel the weight is reasonable. We had planned initially for a fighter in the 5.5 tonne category but currently it has grown to about 6.5 tonne. The penalty of the weight increase is visible in one or two performance parameters. Some parameters like the sustained turn rate and the severity of other performance requirements earlier are not there now because of change in weapon systems. Particularly guided missiles, which today are all aspect missiles slaved to Helmet Mounted Display Systems (HMDS), advanced electronics and radar. Due to the weight growth, there have been certain deviations in the performance parameters. The IAF has validated these deviations to be compensated by advanced weapon systems which were not available in 1985. We will not incorporate any changes in the Mk-1 version as it is ready for production. In the Mk-2 version of Tejas, we expect to see weight savings of around 300 to 500Kg which will come from weight optimisation in the aircraft structures alone.
What is required to ensure CEMILAC clearance will be obtained in December, followed by the IOC?
The CEMILAC clearance is actually a ‘Release to Certification’, with this certification the Tejas can be cleared for use by the operator i.e. IAF. It was being flown till now by pilots belonging to the National Flight Test Centre (NFTC), the ‘Release to Certification’ will see the Tejas being flown by operational pilots of the IAF. To get CEMILAC certification, a process begins and we have to capture all data that has been generated over the last 20 years and put it through filters to address problems if any. CEMILAC will check all the data we provide and match performance figures for the aircraft and then they approve as a third party agency, the ‘Standard of Preparation’. This will happen by December. We have around 300 people working on all the design data generated and double checking the same. We have not encountered any major issues as part of the certification process so far. In the LCA programme, quality has been given the highest priority.
The IOC is an understanding with the users i.e. IAF, telling CEMILAC to clear the aircraft in this particular standard of preparation. We will be providing the IAF with an aircraft that is equipped with a specific set of sensors, weapons, avionics, etc. and a particular standard of performance and functionality as declared in the ‘Standard of Preparation’. The IOC is a nomenclature used by the IAF and the ‘Release to Certification’ is provided by CEMILAC. The IAF will move towards FOC for the Tejas in 2014. We have to add a new CCM, BVR, extra weapons and it will also have a mid-air refueling system along with new drop tanks and few other refinements. We look at adding these features in the second lot of 20 aircraft.
Key.Aero Network
Originally Posted by Arrows
Network -
Key Publishing Ltd Corporate
Key.Aero - The Homepage of Aviation