LCA Tejas: An Indian Fighter - With Foreign Help

 

India’s Light Combat Aircraft program is meant to boost its aviation industry, but it must also solve a pressing military problem. The IAF’s fighter strength has been declining as the MiG-21s that form the largest component of its fleet are lost in crashes, or retired due to age and wear. India’s other Cold War vintage aircraft will face similar problems in the near future.

In response, some MiG-21s have been modernized to MiG-21 ‘Bison’ configuration, and other current fighter types are undergoing modernization programs of their own. The IAF’s fading hope is that India can maintain their fighter numbers until the multi-billion dollar 126+ plane MMRCA sale delivers replacements. Which still leaves India without an affordable overall solution. MMRCA can replace some of India’s mid-range fighters, but what about the MiG-21s? The MiG-21bis program adds years of life to those airframes, but that extended lifespan is still quite finite. By 2020, they’re likely to be gone.

That’s why India’s own Tejas Light Combat Aircraft (LCA) project is so important to the Indian Air Force’s future prospects, and why India’s rigid domestic-only policies are gradually being relaxed, in order to field an operational and competitive aircraft. Even with that help, however, the program’s delays are a growing problem for India. Beyond India, the west’s near-abandonment of the global lightweight fighter market means that choices made in the LCA’s design will also affect its export potential. Which, in turn, feeds back into the overall program’s lifetime costs and viability

LCA Tejas: India’s Lightweight Fighter

Tejas, side view

Within India’s force structure, the LCA is largely expected to replace its 400 or so MiG-21 aircraft with a more versatile and capable performer. The MiGs are being retired as age claims them, and even India’s 125 or so upgraded MiG-21 ‘Bisons’ are only scheduled to remain in service until 2016. The LCA’s overall performance is expected to be somewhat similar to India’s Mirage 2000s, with lower top speed but more modern electronics.

The Tejas LCA design uses a tailless compound delta plan that is designed to be unstable, but controllable thanks to advanced flight software and quadruplex fly-by-wire technology. The aircraft is intended for a 9g / -3.5g flight range, and advanced composites, often using co-cured cobonded technology, make up more than 40% of the Tejas airframe including the wings, fin and fuselage. The radome is made of Kevlar.

Composites help to save weight, and can also lower the plane’s radar profile, depending on where they’re placed. Japan’s F-16-derived F-2 fighters also made heavy use of composite technologies, and found some issues with delamination and cracking that required repair and changes. Static and fatigue strength studies on finite element models, and aeroservoelastic studies, have been performed on the Tejas design; nevertheless, only testing and actual service will reveal how it fares.

Preliminary statistics indicate that the Tejas will have a thrust:weight ratio of close to 1:1 in “clean” (unarmed) configuration; the initial Mark I version’s F404-IN20 power plant is rated for 18,700 lb/ 83.18 kN. Maximum speed is expected be about Mach 1.8, though Tejas will not have Mach 1+ supercruise; like most fighters, it will spend the vast majority of its flight time at subsonic speeds. 7 pylons (3 on each wing, one centerline) will allow it to carry up to 4,000 kg/ 8,800 lbs. of weapons, electronics pods, and/or external fuel, up to the maximum takeoff weight of about 12,500 kg/ 27,500 lbs. Unrefueled range is reportedly 850 km/ 460 nm, though this will vary with weapons and fuel loads. Air-air refueling capability can be used to extend that range, if necessary.

Confirmed combat accoutrements will include:

• MIL-STD-1553B databuses
• IAI EL/M-2032 radar
• Elbit DASH helmet-mounted display
• RAFAEL Derby medium range air-to-air missile
• Vympel R-73/AA-11 “Archer” short range air-to-air missile
• RAFAEL LITENING surveillance & targeting pod

The following sub-section goes into more detail about their rationales and capabilities, and discusses other equipment in this area.

Radar Love: Weapons & Fire Control

EL/M-2032

The plane’s avionics architecture is configured around a 3 bus, distributed MIL-STD-1553B system, using a 32-bit Mission Computer (MC) and software written in Ada. A “glass cockpit” of display screens will provide pilot information, supplemented by Elbit’s DASH helmet-mounted display for commonality with other IAF aircraft.

Radar Failure & Replacement

The Tejas project’s original radar, like its original engine choice, very nearly sank the project entirely. The state-run Aeronautical Development Agency had originally intended to use Ericsson Microwave Systems’ PS-05/A, but decided to develop its own instead. India’s Multi Mode Radar (MMR) program was started in June 1991, with a “Probable Date of Completion” of 6.5 years. More than 15 years later, development was still ongoing as a joint effort by Hindustan Aeronautics Limited in Hyderabad, India’s Electronics and Radar Development Laboratory in Bangalore, and the Centre for Airborne Studies. Even worse, test results for the radar were poor.

By August 2007, even India’s MoD finally admitted that MMR faced serious problems. Radar co-development has now been initiated with Israel’s IAI Elta. Meanwhile, they have offered the EL/M-2032 as an interim solution for Tejas testing and initial fielding, and are discussing the more advanced EL/M-2052 AESA.

IAI’s EL/M-2032 multi-mode radar was originally developed for Israel’s Lavi fighter, and looks set to equip Indian Tejas fighters for the foreseeable future. It already equips India’s Sea Harrier fleet and Jaguar IM strike aircraft., and is popular around the world. It can also be found on some F-16s in Israel and elsewhere, Kfir C10s flown by some Latin American customers, Chile’s upgraded F-5s, Romania’s MiG-21 Lancer upgrades, and South Korea’s F/A-50 lightweight fighter. The radar features modular hardware design, with software control and flexible avionic interfaces, and a TWT coherent transmitter with a low-sidelobe planar antenna. The M-2032 functions in several air-to-air modes, as well as the air-to-ground, air-to-sea, ground-mapping in RBS, DBM, SAR with moving target tracking, and terrain avoidance modes.

Detection and classification ranges will vary depending on the aperture size. A radar adapted to fit in an F-5’s narrow nose will have lower performance than one that fits into a larger F-16. The Tejas’ dimensions suggest that performance may be near the radar’s claimed 80 nautical mile maximums for detection of fighter-sized objects.

Weapons

SPYDER Systems
(click to view full)

Unsurprisingly, RAFAEL’s Derby radar-guided fire-and-forget missile will serve as the Tejas’ initial medium range air-air armament. It lacks the range and datalink of Raytheon’s AMRAAM or Russia’s R-77/AA-12, but it has already been integrated with the EL/M-2032 on India’s own Sea Harriers, and equips India’s forthcoming SPYDER mobile anti-aircraft missile systems. Derby reportedly has good seeker cone coverage, which improves performance within its range. In practice, positive identification requirements have kept most aerial fights within that range, anyway. If India’s own Astra MRAAM continues to progress, it might be integrated later, and supplant Derby.

For shorter-range engagements, Derby will be complemented by Russia’s infrared-guided Vympel R-73/AA-11 “Archer,” giving Tejas partial weapon commonality with India’s large MiG fleets. In an area where radar compatibility isn’t critical, this was a decisive advantage. The R-73 is known for its exceptional maneuverability and “wide boresight” seeker cone, a combination that inaugurated the era of 4th generation missiles. There’s even a rear-facing version, which offers enemies a nasty surprise. Its main competitor was believed to have been RAFAEL’s Python 4/5, which doesn’t need to face backward in order to hit targets behind its fighter.

Tejas planes are expected to carry a range of ground attack weapons, from ordinary bombs and unguided rockets to precision munitions.They will carry RAFAEL’s LITENING advanced surveillance and targeting pod, giving them long-range looks at ground targets, independent laser designation capability, and (rumored) fleet commonality with India’s Jaguars, MiG-27s, Mirage 2000s, and SU-30MKIs.

Tests for unspecified laser-guided bombs and cluster bombs are expected, along with Russian S-8 80mm rockets, and Russian Kh-31/35/39 anti-ship and precision strike missiles. Unfortunately, the MIL-STD-1553B data bus will be an obstacle to integrating GPS-guided weapons. That’s a significant and puzzling omission, given the expected future growth of GPS in weapon guidance.

Engines & Alternatives

F414-GE-400 engine

With its radar issue solved by a foreign partnership, the fighter’s indigenous Kaveri engine (vid. Appendix B) was left as the project’s biggest unresolved issue. That was resolved with a stopgap, followed by a competition to field a working engine; even so, India’s DRDO continues to pour dollars and time into Kaveri development.

The removal of American arms trade sanctions allowed smooth incorporation of a slightly modified F404-GE-IN20 turbofan in initial Tejas Mk.I production models. The engine weighs about 1,000 kg/ 2,200 pounds, and has produced 19,000 pounds of thrust on afterburner during static tests.

Over the longer term, an international competition for the Tejas Mk.II’s engines had 2 shortlisted competitors.

Eurojet’s rival EJ200 equips the Eurofighter Typhoon. It weighs about 1,000 kg and produces 13,500 pounds of thrust in normal operation, or 20,000 pounds of thrust with afterburners. There were even rumors of a thrust-vectoring version to improve Tejas maneuverability.

GE’s F414 is that company’s more advanced alternative to the F404 family that equips the Tejas Mk.I; it currently equips Saab’s JAS-39NG Gripen and Boeing’s F/A-18 Super Hornetfamily. It weighs about 2,300 pounds, and can reportedly produce up to 22,000 pounds of thrust on afterburners, but GE has been remarkably coy about its thrust in normal operation. The figures it supplied to India were obviously good enough, however, because the F414 won.

If the Tejas Mk.II ends up with an alternate engine program, it will have to come from a successful Kaveri follow-on, which is under negotiation as a partnership with French engine maker Snecma. DRDO still hopes to offer this option, and convince India’s politicians to mandate it for Tejas Mk.II retrofits.

Unfortunately for the air force, new engines usually mean changes in size and weight distribution, which require changes to a fighter’s design in order to compensate. If an LCA MkII is produced with a different engine, it can also be expected to feature some design changes and additions in order to rebalance the aircraft, add newer technologies, etc. That can be expected to take at least a year, and usually take several years. Sweden’s JAS-39 Gripen, which made a similar shift from Volvo’s F404-derived RM12 in the JAS-39 A-D models, to GE’s F414 for its new JAS-39NG, offers an excellent example.

In the short term, this means that a successful Tejas program is likely to either produce more LCA Tejas Mk.I aircraft than just the initial production run of 48, or accept fielding delays and the risk of expensive rework to initial production Tejas Mk.II planes.

In the Navy… Naval LCA

Indian officials were interested in an improved engine for 2 reasons. One is simply better performance, thanks to an improved thrust:weight ratio. Another is the need for additional thrust, in order to operate the Tejas successfully as a naval aircraft.

The initial prototype will be powered by the same GE F404 engine that powers the IAF variant, but production versions will use an improved F414 engine. Other changes to the naval Tejas are expected to include:

• Dropped nose, for better visibility in high angle-of-attack (nose pointed up) landings
• Leading edge vortex controls that can extend from the edges of the main wing. They help the aircraft sink faster while remaining safe, in order to land in smaller spaces, and can also improve takeoff response.
• Arrester hook to catch landing wires
• Strengthened spine and related systems, to absorb the high impact of carrier landings
• Longer, strengthened undercarriage
• Powered nose wheel steering for better maneuverability on deck
• Fuel dump system that can shed 1,000 kg of fuel from the fighter’s wing tanks, in case of an emergency just after take-off. Fuel weighs a lot, and that added weight can imperil the attempted emergency landing.

Variant paper designs have been produced to this end, and an initial order placed in 2009 began turning those designs into prototypes. A 2012 decision gave the go-ahead for initial production of 8 planes, but that isn’t a contract yet.

LCA Tejas: Program, Prospects, and Future

India’s LCA Programs
(click to view full)

The Tejas Light Combat Aircraft program began in 1983, and is currently in Full-Scale Engineering Development (FSED) Phase-II, under which India’s DRDO was trying to deliver production fighters to the IAF by December 2010. Initial Operational Clearance wasn’t granted until January 2011, and then only with significant waivers. Limited Series Production aircraft in final configuration have arrived, but IOC issues aren’t expected to resolve until June 2011, most weapons haven’t been tested yet, and full operational clearance (FOC) as a day/night, all-weather platform isn’t expected until December 2012. Final Operational Clearance for induction, and formation of a Tejas squadron at Sulur Air Base in Tamil Nadu, isn’t expected until 2013. The first test-flight of the improved and re-engined Tejas Mark-II is currently scheduled for December 2014, with production beginning in June 2016.

When it was originally approved in 1983, the Tejas program’s cost was set at Rs 560 crore (5.6 billion rupees). The cost had risen to over 3,300 crore by the late 1980s, and has continued to rise since. The Times of India places the 2011 program total at 17,269 crore/ $3.77 billion for all variants. So far, 40 Tejas Mk.I fighters have been ordered. Current plans call for another 100 aircraft (mostly Mk.II) for the air force, and up to 60 naval variants for the Navy.

The Tejas Light Combat Aircraft’s exact per-plane flyaway price point is not known yet, but the goal is an inexpensive fighter in the $20-25 million range, with performance that compares well to early model F-16s and Mirage 2000s. That combination could make this aircraft a capable export contender around the 3rd World; likely competitors include the market for second-hand F-16s, the Chinese/Pakistani JF-17, and Korea’s T/A-50 Golden Eagle supersonic trainer and light fighter. The Russian MiG-29S/M multi-role fighter may also become a competitor, depending on Russia’s chosen pricing approach.

Before exports can become a reality, however, the Tejas must achieve success in India.

Tejas: 2 views

Press Trust of India reports Bangalore-based Aeronautics Development Agency (MoD ADA) R K Ramanathan as promising a 2010 in-service date, while touting a reduction from over 30,000 components to around 7,000. The cranked-delta LCA has already undertaken about 1,500 test flights, and plans to field 40-48 aircraft into the first 2 air force squadrons remain on track, but the IAF’s longer term commitment is less certain. They are taking something of a “wait and see” approach, until the final aircraft is delivered with working systems and the “Tejas Mark II” design has shown what it can do.

One the one hand, the project’s long development period, and DRDO’s past performance on defense projects, tend to justify that wait-and-see approach. On the other hand, the project can easily run into danger without adequate military and political backing. On Feb 6/06, The Telegraph in Calcutta reported that:

“Though air headquarters has not said so in public, it is weighing whether it should commit funds because it is anticipating a resource crunch for the big ticket purchases of multi-role combat aircraft – that could cost the exchequer more than $5 billion over 10 years – and other equipment that it has projected as an immediate need.”

The rumored growth of the MRCA foreign fighter program to 170-200 aircraft, naval plans for 32 more ships in the next 10-15 years, and other planned capital purchases do indeed have the potential to squeeze the Tejas. In return, confidence in the Tejas, or the lack of it, will influence India’s choices in the MMRCA buy of 120-200 foreign fighters – an influence that will be reciprocal. The fewer MMRCA aircraft that India can afford at a flyaway price tag of $35 – 120 million, the more attractive a sub-$25 million Tejas looks in order to plus up numbers – as long as it can in fact be produced to that cost level, be delivered on time, and perform at an adequate level.

Every one of those variables is currently in play.

At present, the worst-case scenario for the Tejas program is truncated production at about 48 aircraft. The generally accepted goal is 7 squadrons, or about 168 planes. The best-case scenario would involve full production for the IAF; a serving STOBAR (Short Take Off via ramps, But Assisted Recovery via arrester gear and wires) naval variant in service by 2020; and export successes that drive up production totals and help to finance future updates.