The Light Combat Aircraft (LCA) a.k.a HAL Tejas for the Indian Navy is 100% indigenous and is being made in India. The indigenous Light Combat Aircraft (LCA) Navy is a Short Takeoff but Arrested Recovery (STOBAR) configuration aircraft designed to suit the Indian Navy’s aircraft carriers. The Shore Based Test Facility (SBTF) built at INS Hansa, Goa specifically as part of this programme represents features available onboard carrier.
The naval version of the aircraft is being tested at SBTF to takeoff from a ski jump ramp with a short runway and also for arrested landing as on-board the carrier.
The tests being carried out include — Carrier fixed wing aircraft mainly fall under three main categories: STOVL (Short Take-Off & Vertical Landing); STOBAR; CATOBAR (Catapult Take-Off But Arrested Recovery).
The challenges in doing a ski jump takeoff, in terms of the aircraft behaviour for a few seconds until wing borne flight takes place is critical to achieving a successful launch (takeoff) from the carrier. For LCA an automated ski-jump takeoff mode has been successfully implemented. The LCA is a highly unstable platform and the fly-by-wire flight control system not only provides stability but also helps to achieve an optimal takeoff through the automatic ski-jump takeoff mode. About 50 ski jump takeoffs have been carried out so far with various possible combinations that are likely to be done by this aircraft onboard carrier.
Another challenging need for this aircraft is the landing onboard carrier. Unlike in the land-based aircraft, owing to the limited space available onboard aircraft carrier, this is achieved through the arrested recovery of aircraft by a special arrangement with cables laid across the flight deck of the carrier. The process of the precise landing of the aircraft with the arrestor hook attached to it to pick up one of the cables (3 cables laid at 12m apart) onboard carrier requires advanced flight control laws to aid the pilot in the task. This also demands very high strength of the landing gear and the airframe. Several combinations of aircraft recovery with Arresting Gear System (AGS) at SBTF have been successfully carried out by arresting the aircraft and bringing it to a halt within 90 metres.
Till date, 28 arrested landings have been successfully achieved without ever missing the arresting wire. However, for the eventuality of a miss of the arresting wire, a “bolter mode” has also been developed. In fact, the bolter mode was tested thoroughly before attempting the first arrested landing.
The successful completion of these tests qualifies this aircraft towards carrying out the next phase of carrier-based testing. This would be done with the availability of the Indian Navy carrier for this purpose.
The naval version of the aircraft is a single-engine aircraft. The tests carried out at SBTF and subsequently, onboard carrier will provide inputs for the design and development of Twin Engine Deck Based Fighter (TEDBF) aircraft sought by the Indian Navy.
Aircraft with STOBAR configuration to operate on Indian Navy carriers – INS Vikramaditya and INS Vikrant. And, mission performance defined with Air Defence as a primary role.
LCA (Navy) Mk2 design and development was taken up with the primary objective of meeting mission performance requirements which was a shortfall in the Navy Mk1. A fresh design with a single higher thrust engine that meets the parameters laid down by the Indian Navy has been achieved. However, Indian Navy has expressed that with newly emerging requirements only a medium weight category twin-engine aircraft would be inducted for operations.
Currently, configuration design of a twin-engine naval aircraft as sought by the user has been initiated. The initial flight testing of this aircraft is scheduled to be carried out by 2026.
Technologies of ski jump take-off and arrested landing to operate from a moving aircraft carrier within the constrained space onboard requires special aerodynamic features, flight control law for safe and precise operations, high strength airframe to withstand arrested landing loads transferred through a specially designed landing gear using indigenously developed special grade maraging steel and customized avionics towards the carrier-based operations.
For the design of the LCA Navy, all the critical technologies like Aerodynamics, Flight Control, Aircraft Structures, Avionics, etc. are 100% indigenous. The Fixed-wing naval aircraft to be operated onboard the carrier is designed with ‘Carrier suitability’ as a very important constraint. Unlike land-based aircraft, that are generic in nature these aircraft are built as the adage goes – ‘Horses for courses’.
The challenges towards achieving an optimal aircraft configuration towards meeting this need to suit the Indian Navy carriers has been demonstrated at the SBTF. This would be followed up by flight trials on the carrier.
The automatic ski-jump take-off, flight control system for a precise approach for the demanding arrested recovery, improvements in aerodynamics, high strength airframe to withstand high sink rate, the landing gear and arrestor hook that enable the safe launch and recovery of this aircraft are completely developed indigenously. Qualification of the system components that experience arrested landing shocks while retaining full functionality has been an indigenous effort.
As far as the equipment on LCA, about 60% of the components are indigenously manufactured. This percentage would increase to beyond 70% in the Twin Engine Deck Based Fighter. This pioneering effort would chart the further course of indigenous naval aircraft in the country.
