By Anantha Krishnan M
Express News Service
Bangalore: India's self-reliance capabilities in taking
up naval aircraft projects in future is sure to get a fillip with the
Aeronautical Development Agency (ADA) and Hindustan Aeronautics Limited (HAL)
beginning the 'countdown of sort' for
the first flight of Light Combat Aircraft (LCA) Naval Prototype (NP-1). The
inspiring bit of this project is probably the maturing of a military industrial
complex and the technological leap of Indian defence units – both
government-owned and private sector.
The unique requirement of
naval aircraft is the complex amalgamation of saline and humid environment of
operation, restricted availability of deck run for launch or recovery and high
operating load conditions. Such intricate needs call for basic design change to
suit the carrier operations leading to strengthening of aircraft structure and
landing gear, inclusion of leading edge vortex control (LEVCON) and arrester
hook, improved engine, enhanced aerodynamic performance and incorporation of
special material.
The LEVCON surface is
fitted at the front tip of the aircraft wing to ensure low landing speed, good
controllability and better vision for the pilot. Such a surface is used on state-of-the-art US
marine aircraft F-18. Usually, in
leading and trailing edges linear actuators are used, however, the LEVCON was a
biggest challenge to the designer as it has to be operated by a concealed
rotary actuator with aerodynamic profiling of the connecting surface. The
rotary actuator was designed in collaboration with foreign vendor.
“It threw related
challenging requirement of testing and certification at a safety factor of 150
percent of maximum working load. The
LEVCON test rig was designed in-house along with a dummy test specimen rotary
actuator with similar specifications to avoid loss of usable item, thus saving
few crores of rupees to the exchequer,” sources told Express.
The feature of launch and
recovery onboard carrier was another herculean assignment to be managed. The
flare-less landing with high sink rate of 7.1 m/sec and heavy thumping with
engine to full throttle till arrested by deck cable, is akin to a controlled
crash of the aircraft on the ship every time it operates. This yields five
times of loading on main landing gear as compared to Tejas. Sources say that in
horizontal direction, the arrested shock recovery produces axial loads on
aircraft structure of the tune of 4.5 g, calling for re-certification of all line
replacement units (LRUs), components and associated systems of naval version to
ensure fail safe operation repeatedly.
“The ramp takeoff switch
ensures that the aircraft is prepared with pre-defined functionality of each
system in ship-borne operational mode. This ensures safe launch at max capable
all-up weight with full fuel and weapon stores from a ship ski jump of 14 deg
ramp profile, when released from deck hydraulic stopper. Such a dramatic launch
imposes harsh loading of nose-landing gear during take-off ski-jump run amounting
to five times of the IAF Tejas values. All of a sudden the landing gear is un-loaded
at the point of exit of the ramp and allowed to extend to its fullest stroke in
a wink of a second,” say sources.
The take-off and landing
logics are integrated in its quadruplex digital redundant flight control system
and open architecture computer for efficient interface between the pilot and the
aircraft with the aim of easing work-load during launch and recovery phase and
fail safe operation.
The LCA Navy is designed
for strict operating conditions and emergency recovery, in that it can bring
back weight to landing limits, quickly by jettisoning 1000 kg fuel in three
minutes with the help of specially-designed fuel dump system. The testing and certification
of unique design features for LCA Navy called for systematic plan of action to
create new test facilities and deep study of certification philosophy.
The ADA has designed and
fabricated various types of simulators, including engineer-in-loop, real-time
software development and maintenance. The shore-based test facility (SBTF) at
Goa with ski-jump launch and arrested recovery similar to aircraft carrier is
ready. The arrester hook test facility, LEVCON test rig and landing gear drop
test rig are also developed in-house.
There are more than 100
agencies involved with the LCA-Navy project. They include DRDO, HAL, CSIR,
PSUs, private sector and academia, spread all over India, ranging from NAL,
CARE, DARE, CVRDE, , DEBEL, LRDE, Midhani, CSIO, TCS, IITs, IISc and Naval
Aviation at NHQ.
Copyright@The
New Indian Express.
BLOGGER'S NOTE: A trimmed version of the
above report appeared in today’s Express. Additional inputs are added to the
above report on the blog for the benefit of Tarmak007’s registered members, regular visitors,
guests and ‘advisors.’ Please note that these information are collated from
different sources in ADA, HAL, Navy and DRDO and stitched together in layman’s language.
While I can vouch for the authenticity of inputs, you may please buzz me if I
go wrong. It is tough to penetrate at times, especially to pocket photos from
multiple sources. The watermarks on the photos are just reminders that these are not supplied to the blogger through some 'annual contract', but sourced by the blogger after constant-chase and follow-ups. Tarmak007 salutes all sources & friends in DRDO, Navy, IAF, HAL and ADA, who
often go out of their way to fetch authentic information on LCA. It has been a huge learning
process for Tarmak007 every time a new project/technology is taken on the write path. I
am delighted that all of you are also part of this inspiring journey!
