Tuesday, March 31, 2020

This Tiny Aircraft Was India’s 1st All-Composite Bird Built In The Country

Small starts, towards big ends.


Somebody looking up the skies of Bangalore, more than 33 years back, in the morning of Thursday, February 26, 1987, could have been treated to the unusual sight of this peculiar-looking aircraft gently flying wafting through the air. Residents of Bengaluru, thanks to the presence of IAF’s bases in Yelahanka & Jalahalli, its Aircraft & Systems Testing Establishment [ASTE], DPSU Hindustan Aeronautics Limited [HAL] haven’t been strangers to the sight of aircraft & helicopters going about their paces over its skies. However, there was something different about this flight & the thing flying.

Light Canard Research Aircraft LCRA 001

Named the Light Canard Research Aircraft [LCRA], the bird was put together by the city-based National Aerospace Laboratories [NAL], then named the National Aeronautical Laboratory. Bearing Tail Number VT-XIU, it highlighted the successful demonstration of an Indian civilian organisation building an aircraft for the first time1. Previous efforts, such as the Hindustan Trainer 2 [HT-2], the HUL-26 Pushpak & successors like the HAOP-27 Krishak were undertaken by the primarily military focussed HAL, which first cut its teeth servicing Allied aircraft during World War II, in its previous avatar as Hindustan Aircraft Limited &, post-independence, locally assembling copies of mostly Soviet birds, under license from their OEM, to cater to India’s defence needs.

Light Canard Research Aircraft LCRA 003

It was, therefore, quite a pioneering effort on part of the NAL to have built and successfully flown this aircraft. Assembling and flying this aircraft provided the organisation with a much-needed flight data generation platform, in addition to enhancing it’s understanding of flight characteristics. The experience & information gathered proved invaluable in pursuit of it’s future endeavours [more on it later].

NAL, functioning under the aegis of the Council of Scientific and Industrial Research [CSIR] began operations in 1959 by providing support & services to India’s Aerospace programmes. Primary achievement included setting up the country’s 1st Wind Tunnel Testing facility, needed to undertake Aerodynamic studies.

It’s attempts, in the 70s, to initiate development of a domestic civilian aircraft, however, came to nought. Then in the 80s, it made the LCRA happen.

Light Canard Research Aircraft LCRA 002

‘Put together’ aptly describes the NAL’s manufacturing role in the Light Canard Research Aircraft project. They built it using the design kit of the Rutan Long-EZ aircraft model, purchased from the American Rutan Aircraft Factory. Founded by Aerospace Engineer Elbert “Burt” Leander Rutan, the Rutan Aircraft Factory Co. was best known for developing the Model 76 Voyager, the first aircraft in the world to have circumnavigated Earth, in a single go, without refuelling.

The following video presentation contains perhaps the only available footage of the NAL-built Light Canard Research Aircraft in flight.

One can see the LCRA, as it progresses, starting from being an organisational vision, to execution &, finally, to flight. As made clear in the title, it had an all-composite body, the first such modern aircraft built in the country. Directionally laid, resin-infused Fiberglass material, used in tandem with multiple polymer types such as Polyurethane, Polystyrene & PVC, each possessing unique properties, fulfilling specific requirements, were used to build the aircraft body. The choice of Composites & Polymers as build material was unsurprising. Besides its high specific strength, corrosion resistance, it also possesses superior tailorabilty, to fashion shapes out of these materials. As seen in the video, using simple Hot-wire Foam Cutter they were able to shape the Polymer blocks into Aero-structure.

Vacuum Enhanced Resin Infusion Technology VERITy - 001

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NAL has, subsequently, gone ahead, undertaking significant research in developing high strength, lightweight Polymer Composite materials and manufacturing technologies. One such outcome has been development of it’s liquid composite moulding process called Vacuum Enhanced Resin Infusion Technology [VERITy].

SARAS Composite Wing Structure - 002Using this process, it successfully demonstrated manufacturing of large structures like the integrated outboard wing of its contemporary Saras civilian transport aircraft.

The LCRA, weighing 600 kilograms, was powered by a single Lycoming O-235 Engine producing 115hp of Power, using a fixed-pitch wooden propeller for thrust. Its design implements a Pusher Propeller configuration, whereby its Engine & Propeller are mounted at the rear of the Fuselage. One major advantage it offers is the reduced drag encountered, since the accelerated air would be able to flow unobstructed, without encountering any hindrances.

As a thumb rule, this would result in energy savings, that would translate into higher aircraft endurance compared to a Tractor Propeller configuration, powered by the same engine. A major USP in a “kitna deti hai?!” country. The pilot’s frontal view also remains unhindered in such a configuration.

Check out this video for a better understanding of the Pusher configuration.

SARAS - ST 7001 - Transport Aircraft - 02

NAL’s appreciation for this configuration has seen it also being implemented in its Saras programme. In addition to the earlier stated advantages, one would also experience lower noise levels inside the aircraft, since with the engine being at the back, its occupant would be moving away from the sound – Doppler Effect. Upon viewing the video linked above & studying the Saras’ design, one can see how NAL has worked towards mitigating the drawbacks encountered by Pusher aircraft, while retaining its benefits.

Light Canard Research Aircraft LCRA 005

At 06:05 onwards in the video, as the Engineers work on readying the LCRA, one can see model of another aircraft at the back. While the exact identity of the model aircraft can not be ascertained – perhaps a LCA design iteration, it does sports a Canard wing. The Long-EZ derivate also features a Canard. Being an additional lifting surface, it allows the aircraft to operate safely at lower speeds, improving Stall performance & flight stability.

The Canard surface has also found appreciation in India’s military programme, having been incorporated in the redesigned Light Combat Aircraft [LCA] Tejas Mk. II, aka, the Medium Weight Fighter [MWF].

Rocket Propulsion CSIR-NAL Firefly - 001-001

NAL has also carried out some experiments with Rocket-propulsion, fixing it atop a scaled-down, unmanned version of the aircraft, christened Firefly. When building the Light Canard Research Aircraft, it believed that this would be the “beginning of an ambitious project to develop experimental aircraft for specific research goals”. How successful it has been in sustaining this is a matter of debate. What is not up for debate, however, was the utility of the LCRA for furthering NAL’s knowledge-base, that it expanded with the application of statistical modelling such as parameter estimation techniques.

Rustom-1 Unmanned Aerial Vehicle UAV - 001

It continued to fly as late as 2003-2004, 17 years after its maiden flight. The spirit of the LCRA lives on today in the form of the Rustom-1 Unmanned Aerial Vehicle [UAV], developed by the Aeronautical Development Establishment [ADE]. It met with initial setback in 2009 when, during its maiden flight, it crashed. Like the mythical Phoenix rising up from the ashes, it successfully flew a year later in 2010. Subsequently, we had been treated to a photograph showing the UAV equipped with a pair of HELINA anti-tank missiles, mounted from it’s underwing pylons. It appears to be an in-house ADE undertaking, since there is currently no Governmental sanction to weaponise the platform. None of the branches of the Indian Armed Forces, at present, have committed to induct the Rustom-1 in its fleet, despite completion of its development cycle. In such time, it could serve as a test-bed to validate technologies for implementation on future UAVs. One surely hopes, however, that it eventually finds favour, in numbers, with Indian end-users, in lieu of imports. This would play a major role in strengthening domestic research and manufacturing. Incremental improvements, based on user input, could be incorporated in subsequent iteration of the platform.

CSIR National Aerospace Laboratories NAL Roadmap - 01

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With the LCRA, NAL kicked the door open for civilian programmes to be undertaken in the country. Subsequent to its Saras & Hansa programme, it has proposed development of a Mark 2 version of the Saras, as well as a 90-seat aircraft, the Regional Transport Aircraft [RTA-90]. Reasons, other than technical have been why these aren’t off the ground yet. It is imperative that indigenous efforts are nurtured, supporting them, since around such projects grows the ecosystem, capable of realising greater, much improved future products. The accretion of indigenous IPR would be yet another invaluable outcome of such India-first policy. Today, it is not uncommon to learn of successful homebrew pursuits in India to build aircraft.

Be the size of the LCRA small, what NAL achieved was huge.

Light Canard Research Aircraft LCRA 004

Godspeed

1 – Speaking of firsts, India was the stage for the world’s first official airmail service. On Saturday, February 18, 1911, with the Maha Kumbh mela underway, a Frenchman named Henri Piquet flew a Coventry-based, Humber Ltd. Co.-built Sommer biplane, from Allahabad to Naini, carrying with him 6500 mails weighing around 15 kilograms. This journey of around 8 kilometres, he completed in approximately 13 minutes. An interesting story of the circumstances surrounding the flight can be read here - 1911: Letters flown for first time by planes, not pigeons.