“Whoever rules the waves, rules the world”, these famous words by the renowned US Navy flag officer, geo-strategist, and naval historian Alfred T. Mahan, highlight the importance of naval power. In modern-day naval warfare, aircraft carrier-borne operations play a major role in establishing superiority over the opponent. The indigenous 4.5x generation Twin Engine Deck Based Fighter (TEDBF) aircraft aims to establish air dominance in the mighty seas from the carrier-borne operations and contribute to the overall naval superiority in the near future for the Indian Navy.
Before we delve into the expected timelines, updates and capabilities of TEDBF, it is important to understand the basics of carrier-borne naval aviation, the current fleet of naval fighter jets with the Indian Navy and the importance of naval LCA (naval variant of Light Combat Aircraft, Tejas) programme in the development of TEDBF.
Basics of Carrier-Borne Naval Aviation: As compared to conventional aviation especially for the fixed wing aircrafts, carrier-borne aviation is more challenging as the aircraft has to take-off from a distance of mere 100-300m and similarly has to land within a distance of about 100m by using arresting wires where 3-4 steel wires (assisted by hydraulic damping systems) are laid on the carrier and when the tailhook of the aircraft engages the wire while landing, it leads to its rapid deceleration. For take-off in case of CATOBAR (Catapult Assisted Take-off But Arrested Landing) aircraft carriers, a catapult system is used for assisted take off using Steam catapult or EMALS (Electromagnetic Aircraft Launch) technologies. In case of Indian Navy, aircraft carriers (viz. INS Vikramaditya and INS Vikrant) are of STOBAR (Short Take-off But Arrested Landing) type where aircraft is launched under its own power using a ski-jump (elevated platform of about 14° angle to assist take-off). For this, the aircraft needs to feature a high Thrust to Weight Ratio (TWR) to generate enough lift to take-off from the carrier.
Current Fleet of Fixed Wing Fighter Aircrafts: The Indian Navy operates medium weight category, twin engine, 4+ generation Mig-29K/KUB aircrafts, geared primarily towards air superiority and fleet defence roles, presently from INS Vikramaditya. It sports an improved engine RD33MK with 7% higher thrust than RD33 engines, FADEC (Full Authority Digital Engine Control) and a rugged air frame for naval operations. But Indian Navy has faced many issues related to the engine, airframe and serviceability of the aircraft in the recent past, viz.:
Engine Defects: Several design related defects were found in the RD33MK engines where about 62% of engines were withdrawn from service as per the CAG Audit report, 2016. There were at least 10 instances where the aircraft had to land using a single engine.
Faulty Fly by Wire System: The Fly by Wire system (where flight controls of an aircraft is managed by an electronic interface) was found to be faulty. There were many instances where after each landing, instrument calibration went for a toss and the aircraft needed to be repaired onboard. Also, interface issues with the Luna Aviation Complex with the Mig-29K, leading to difficulties in synchronizing landings were found.
Airframe Defects: Several airframe defects during deck trials on sortie to sortie basis were reported by Directorate of Air Support Equipments on June, 2014.
Reduced serviceability & operational availability: The serviceability, maintenance & operational availability were affected due to engine defects, faulty FBW system and less availability of spare parts.
Also in the past decade since Mig-29K/KUB induction in 2011, there have been 4 instances of the crash of the aircraft, the recent one on Nov 2020 where 1 pilot lost his life. This raises serious questions regarding pilot safety too. Although the mentioned issues with Mig-29K have been improved to some extent in recent years, the operational availability of Mig-29K/KUB still seems to be low which is evident from the fact that the Indian Navy plans to induct 26 carrier-borne fighters (where Rafale-M from France & F/A-18 Super Hornet from the U.S. are the main contenders) as a stop-gap for the upcoming indigenous aircraft carrier INS Vikrant (to be commissioned this year) with expectations that the indigenous TEDBF would take-off by 2026 & its induction would start by 2031.
Role of Naval LCA Tejas (N-LCA) in TEDBF Development: N-LCA programme commenced in 2003 and the first prototype NP-1 was rolled out in July 2010 followed by flight tests the subsequent year. Initial development of the N-LCA was slow due to the modification of Air force version of LCA Tejas and understanding the challenges in developing the naval aspects of the aircraft. These challenging naval aspects includes modification of airframe structure including strengthening of undercarriage (to absorb shocks of carrier take-off and arrested recovery), drooped nose for better visibility, modifications of fuel systems; addition of aerodynamic aspect, software controls etc. In December 2016, due to the long delay and technical reasons such as inadequate TWR (thrust to weight ratio) of N-LCA for carrier based combat operations, Indian Navy decided to pull out from the N-LCA programme but ADA (Aeronautical Development Agency) decided to continue the test flying in order to attain technical maturity for the programme which later proved to be critical in the development of TEDBF. In January 2020, Commodore Jaideep Maolankar successfully carried out the take-off and landings (a total of 18 sorties in 5 days) of NP-2 prototype of N-LCA from the aircraft carrier INS Vikramaditya.
As per Vinod Kumar T.V., Project Director of TEDBF, important lessons learned in the N-LCA programme which were taken forward to TEDBF development includes the understanding of carrier interface, carrier suitability, launch capability from ski-jump of 14⁰ angle, take-off from a distance of 200m or even less at both aircraft carrier and SBTF (Shore Based Test Facility at INS Hansa, Goa), the recovery phase of aircraft, aerodynamics and flight mechanics expertise etc.
Twin Engine Deck Based FighterThe TEDBF (Twin Engine Deck Based Fighter) is a 4.5x generation multirole combat aircraft currently under development by ADA (Aeronautical Development Agency) for the Indian Navy which is stated to replace Mig-29K by 2031.
Timeline & Updates in TEDBF programme:
In April 2020, ADA announced that they’re working on a new design of naval aircraft as per Indian Navy’s MRCBF (Multi-Role Carrier Based Fighter) requirements to replace Mig-29K/KUBs.
Government approval for the project was given nod in mid-2020 for which ₹13,000 crore will be sanctioned, currently 40% of the initial development of TEDBF is funded by the Indian Navy.
At the start of 2021, the Concept Review (design) stage was initiated and two designs were proposed: a) Delta-Canard Design, b) Trapezoidal design with tail stabilisers.
The Concept Review (design) stage was completed by December 2021 and Delta-canard design iteration has been chosen and Preliminary Design Review (stage where new technologies are tested & if mature enough, are integrated to the product subsystem) has been initiated.
TEDBF’s first flight is planned in 2026 and is set to enter production in 2031. As far as timeline of the programme is concerned, as per ADA Chief and Project Director (Combat Aircraft), Dr. Girish S. Deodhare, ADA is confident about the timelines as most of the technologies used in TEDBF are already proven in LCA Tejas & associated programmes.
Design: The design of TEDBF can be seen as the consolidation of the technologies developed and validated in the LCA Tejas and associated projects into a complete new design. The engine intakes and close-coupled canards are similar to Tejas Mk2. One of the distinct features in the front fuselage is introduction of LERX (Leading Edge Root Extension) which along with the close-coupled canards will provide significant Lift to Drag ratio which will assist the aircraft in smooth take-off from the ski-jump with significant payloads. The delta wing configuration is similar to that of Eurofighter Typhoon, which acts as a rear stabilizer to provide stable lift to the aircraft (by generating negative lift at higher wind speeds). The shape of the front fuselage is made stealthier to reduce the RCS (Radar Cross-Section area) rendering it less detectable to Radars. Like Mig29-K/KUB, it will feature wing folding to suit the Indian Navy aircraft carriers. Also, DSI (Diverterless Supersonic Inlet ) will be featured which will help in the controlled and better air flow into the engines, weight reduction and reduced radar signature, thus improving stealth.military
Engines &Weight capacity: It will feature 2× F414 engines from General Electrics, US, with 58.5kN dry thrust and 98kN wet thrust (with afterburner) which will enable the aircraft an MTOW (Maximum Take-off Weight) of 26 tons.
Radar, Sensors, Electronic Warfare Suite & Cockpit:
Radar: Upscaled indigenous Uttam AESA (Active Electronic Scanned Array) radar will be featured in the aircraft.
Sensors: Similar to Tejas Mk2, TEDBF is set to feature a variety of indigenous sensors developed by DARE (Defence Avionics Research Establishment), such as Indigenous Infrared Search and Track (IRST) system for passive target acquisition to be featured at the nose plug of the aircraft. Indigenous RWR (Radar Warning Receiver, most probably the next generation RWR DR-118 by DARE) at the tailfin.
Electronic Warfare Suite: It will sport an integral Unified Electronic Warfare Suite (UEWS) and a dual colour Missile Approach Warning System (MAWS) also developed by DARE.
Cockpit: The Cockpit will feature the state-of-the-art Large Area Display with sideways Hands On Throttle And Stick (HOTAS) for better view and comfort of the pilot.
Wingspan: Like Mig-29K/KUB, TEDBF will feature wing folding options, with the unfolded wingspan of 11.2m and folded wingspan of 7.6m. These dimensions will enable the aircraft to fit within the lift dimensions in both the carriers INS Vikramaditya and INS Vikrant.
Weᴀponѕ: TEDBF will have a total of 13 hardpoints that carry a wide variety of weᴀponѕ along with the external fuel carrying drop tanks. It is likely to feature a mix of indigenous & foreign weᴀponѕ like Astra Mk1, Astra Mk2 (under development), NGCCM (New Generation Close Combat Missile) most likely ASRAAM from European consortium MBDA, Harpoon Anti-Ship missiles, Precision Guided Munitions like Hammer and Spice 2000. The weᴀpon Spectrum is expected to be even wider depending upon the type of mission carried out.
Semi-Stealth Aspects: Stealthy frontal fuselage design, use of 90% by surface area Carbon-Fibre Composites, Radar Absorbent Material (RAM) coating, Indium-Tin Oxide coating on canopy to prevent radar reflections on Pilot’s helmet, S-shaped air intakes which prevent line-of-sight of the engine from radar signatures and software derived canard positions for minimal radar deflections may lead to a low overall RCS for TEDBF, rendering it less detectable to radars.
Based on the active participation in the N-LCA programme and watching the developments, challenges and achievements closely along with ADA, the Indian Navy is confident and upbeat about the TEDBF development. The support of the Indian Navy for the indigenous equipment is unparalleled and that’s one of the primary reasons it is fondly known as the ‘Builders Navy’. The TEDBF is an important programme not only for the Indian Navy, its success may also open the doors for its Air Force variant ORCA (Omni-Role Combat Aircraft) and even for exports. It is an important programme in moving Indian Aerospace Industry an inch closer towards self-reliance and contributing towards ‘Atmanirbhar Bharat’.