In 2003, based on the progress made on the Air Force LCA Programme the Govt approved Phase-1 development of 2 LCA Navy Prototypes that would operate from an aircraft carrier with the concept of Ski-jump Take-off and Arrested Recovery (STOBAR). Navy actively supported this Challenging programme to design, develop, build and flight test a carrier borne aircraft for the first time in the country. The two prototypes under development would be used to demonstrate that the aircraft is capable of operating from a ship, i.e., carrier compatible.
The question often asked is ‘what are the changes in LCA(Navy) in comparison to the Air Force version?’ Typically the aircraft will get airborne in about 200m over the ski-jump on the ship as against a land based take-off run of about 800m. Landing on the ship is with an arrester hook on the aircraft engaging an arrester wire on the ship and the aircraft stops in 90m which is about 1/10th land based stopping distance.
Unlike shore based take-off and landing applications, typical ship borne requirements imposes large loads on the aircraft structure which entails new design. Also, the nose section of the aircraft is drooped down in order to have better pilot vision for ship landing. Whilst the external aerodynamic shape of the aircraft is same as the Air Force Trainer, the internal structure is entirely different due to larger loads resulting from carrier operations. However, all Mechanical, Avionics and Flight Control system layout are by and large common with the Air Force version. The design of LCA(Navy) has been performed in a 3Dimensional Computer Aided Design (CAD) concurrent engineering environment. A Digital Mock Up (DMU) of the aircraft was ultimately created which had all the internal equipment laid out. This helped in visualising possible areas of clash with various system groups and the structural interfaces due a possibility of ‘virtual walk through’. No physical mock up has been built. Due to first time design, there could be additional reserve factors taken as a conservative measure, but would be optimised based on experience in the future prototypes. This would result in significant weight savings.
Areas identified as challenges over and above the Air Force Version were structural design, Landing gear design, arrester hook, introduction of a new control surface (LEVCON) and ski-jump take-off. A case in point for Naval specific activities was the development of large sized landing gear forgings. Midhani had to develop the special tooling and processes and provide the special steel forgings. In addition, Bharat Forge, Pune provided the near shaped forgings of the major landing gear elements. These have been fabricated at private companies at Hyderabad and landing gears have been assembled at HAL (Nasik). Some of the typical challenges encountered during the development cycle, resulted in them taking longer than anticipated. However, today these have been resolved and we all await the aircraft’s rollout in the presence of the Hon’ble Raksha Mantri and the Chief of the Naval Staff.
In its primary role of Air to Air combat, the aircraft will carry both Close Combat Missiles (CCM) and Beyond Visual Range (BVR) Missiles. In its Air to Sea role, the aircraft will carry Anti Ship Missile (ASM). The aircraft can carry external fuel drop tanks to increase range and endurance. The aircraft can carry a wide variety of bombs based on role requirement.
To meet specific Naval testing, new test facilities have and are being developed. A new landing gear drop test facility has been created to handle testing to Naval requirements for qualifying larger landing gear loads. A hardware-in-loop simulation for flight control system testing called ‘Iron-bird’ has been set up and functioning. In this facility, entire hydraulics, flight control system and avionics would be integrated for the evaluation of the software. The Avionics and Weapon test rigs have been suitably modified to test the changes in system layout and architecture required for the Naval version. Shore Based Test Facility (SBTF) to simulate an aircraft carrier with ski-jump and arrested recovery is being set up at the Naval Air Station at Goa. The ski-jump facility is expected to be ready by the last quarter of 2011 and the landing area a year later. Goa Shipyard Ltd is handling the complete structural work, system integration and operations. R&D Engineers and CCE(R&D) west Pune are handling the civil works. Specialised equipment supply is from Russia in order to have the same configuration as on the Vikramaditya.
It is critical to demonstrate carrier compatibility to infuse confidence in the Indian Navy that we indeed have a Carrier borne aircraft and towards that it is critical to demonstrate ski-jump take off and validate the simulations that have been carried out by the control Law team. Navy has defined the Mission and Performance requirements expected of the aircraft. As mentioned earlier, due to first time design, there may be shortfall in certain parameters with the current engine. Two more LCA(Navy) prototypes has been sanctioned by the Govt in Dec 2009 with a higher thrust engine to enable meeting the Mission objectives set out by the Navy.
The act of ‘Rollout’ is a significant milestone in the development process of an aircraft wherein it is structurally complete, equipment installed, plumbing and wiring completed. The aircraft is on its wheels and can be moved by assisted power and is a precursor to the phase of ground based system integration testing leading the engine ground run, taxi tests and flight. Every effort is being made by all the stake holders to have the maiden flight in 3 to 4 months time.
This day of NP1 rollout has been possible with the active involvement of HAL as the Principal Partner of ADA and support by DRDO, CSIR labs, CEMILAC, DGAQA, Public and Private sector industries, Educational Institutions and a host of other agencies. I wish to salute all of those who have contributed as a composite LCA Navy Team in realising this important milestone and look forward to the same spirit to take the aircraft towards its maiden flight at the earliest.