The missing Malaysian
airways flight, MH370, has raised many questions on flight surveillance and
tracking system. It has brought the debate of technological advancements and
flight mystery at the forefront. Though with technological revolutions and satellite
communication advancements, individual’s movements on the surface of the earth
are being tracked, the flight in air (space), suddenly disappeared, posing
challenges to our tracking mechanisms. It is therefore necessary to understand
the existing aircraft tracking system so as to decipher what went wrong on
flight MH370 !
Present Aircraft tracking system:
Air traffic
control standard international
practice is to monitor airspace using two radar systems: primary and secondary.
Primary radar, based on the earliest form of radar developed in the
1930s, detects and measures the approximate position of aircraft using
reflected radio signals. It does this whether or not the subject wants to be
tracked. Secondary radar, which relies on targets being
equipped with a transponder, also requests additional information from the
aircraft - such as its identity and altitude.
All commercial aircraft
are equipped with transponders (an abbreviation of "transmitter
responder"), which automatically transmit a unique four-digit code when
they receive a radio signal sent by radar. The code gives the plane's identity
and radar stations go on to establish speed and direction by monitoring
successive transmissions. This flight data is then relayed to air traffic
controllers. However, once an aircraft is more than 240km (150 miles) out to
sea, radar coverage fades and air crew keep in touch with air traffic control
and other aircraft using high-frequency radio.
Can't planes be tracked with GPS?
Yes, but while GPS
(Global Positioning System) is a staple of modern life, the world's air
traffic control network is still almost entirely radar-based.
Aircraft use GPS to show
pilots their position on a map, but this data is not usually shared with air
traffic control.
Some of the most modern
aircraft are able to "uplink" GPS data to satellite tracking
services, but handling large volumes of flight data is expensive and such
systems are usually only used in remote areas with no radar coverage.
The satellite data which
suggests flight MH370 flew on for several hours are basic 'pings' sent by the
plane, and so far only help to identify two very approximate flight corridors
north and south.
New Technology
Over the next decade, a
new system called ADS-B (Automatic Dependent Surveillance Broadcast) is expected to replace radar as the primary
surveillance method for air traffic control. ADS-B will see aircraft work out
their position using GPS and then relay data to the ground and other planes.
But, as with existing
secondary radar, ADS-B coverage does not extend over the oceans. ADS-B is
already used by flight-tracking websites, but the Malaysian aircraft
disappeared from these at the same time it vanished from air traffic control
screens.
Could other data systems provide clues?
When Air France flight
447 crashed into the mid Atlantic in 2009, its onboard data system -Aircraft Communications
Addressing and Reporting System (ACARS) - gave investigators an early
insight into what had gone wrong. ACARS is a service that allows computers
aboard the plane to "talk" to computers on the ground, relaying
in-flight information about the health of its systems.
Messages are transmitted either by radio or
digital signals via satellites, and can cover anything from the status of the
plane's engines to a faulty toilet. This provides ground crews with vital
diagnostic information, allowing maintenance to be carried out more quickly. In
the Air France case, ACARS highlighted faulty speed readings, which caused the
air crew to become disorientated.
However Malaysian officials believe that the
ACAR system on the Boeing 777 was deliberately shut down before the final radio
message was exchanged at 01:19. Turning off ACARS is no easy feat, requiring a
person with technical knowledge to climb down through a trapdoor into the
plane's hull to remove circuit breakers.
What is Black Box in
aviation?
Any commercial aeroplane
or corporate jet is required to be equipped with a cockpit voice recorder and a
flight data recorder. It is these two items of separate equipment which we
commonly refer to as a ‘Black Box.’ While they do nothing to help the plane
when it is in the air, both these pieces of equipment are vitally important
should the plane crash, as they help crash investigators find out what happened
just before the crash.
To help locate the
cockpit voice recorder and a flight data recorder in the aftermath of a plane
crash that occurs at sea, each recorder has a device fitted to it known as an
Underwater Locator Beacon (ULB). The device is activated as soon as the
recorder comes into contact with water and it can transmit from a depth as deep
as 14,000 feet. Also, to help investigators find them; a Black Box is not
actually black at all, but bright orange.
The mystery of flight
MH370 may only ever be solved when the aircraft's "black box"
flight recorders are recovered. However, retrieving them from the sea is
not easy. In the case of Air France flight 447, it took nearly two years. If
under water, the boxes emit ultrasonic signals - but these signals have a
limited range, and search crews may not detect them unless close to the crash
site.
Possibility of “terrain masking” used by MH370
Officials searching for missing Flight MH370 are also investigating
the possibility of terrain masking i.e. probing the possibility that the plane hugged close to the
ground to avoid detection – a technique generally used by military pilots.
The inquiry into the possibility that the plane was “terrain
masking” might help explain why as of yet, there has been no fixed record of
the jet since it was captured as a “blip” on a Malaysian military radar at
2.15am on Saturday March 8. At that point it was north-west of Penang.
The missing plane MH370
has raised many questions on the Plane tracking technology available with
aviation industry. It is high time for the industry to shift to full proof
mechanism, so that the planes may directly be tracked from ground without an
error. This will help in averting any future mishaps and mysteries and will be
in the larger interest of humankind.
Note: Views are personal


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