“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.