The British company that provided
vital information on MH370’s whereabouts explains its calculations
The Malaysian government has concluded that,
based on satellite data analysis from British company Inmarsat, Malaysian
Airlines flight MH370 ended in the Indian Ocean, and no one on board survived.
In a press statement this afternoon, Prime
Minister Najib Razak said that, using a type of analysis "never before
used in an investigation of this sort", Inmarsat engineers have been able
to establish that the plane's last position was in the middle of the Indian
Ocean, west of Perth.
"This is a remote location, far from any
possible landing sites. It is therefore with deep sadness and regret that I
must inform you that, according to this new data, flight MH370 ended in the
southern Indian Ocean."
Inmarsat’s role in the search for Malaysian
Airlines flight MH370 began immediately after the aircraft
disappeared.
Although the main aircraft communications addressing and reporting system
(which would usually transmit the plane's position) was switched off, one of
Inmarsat’s satellites continued to pick up a series of automated hourly 'pings'
from a terminal on the plane, which would normally be used to synchronise
timing information.
By analysing these pings, Inmarsat was able to
establish that MH370 continued to fly for at least five hours after the
aircraft left Malaysian airspace, and that it had flown along one of two
'corridors' – one arcing north and the other south. The plane was reportedly
flying at a cruising height above 30,000 feet.
"We looked at the Doppler effect, which is
the change in frequency due to the movement of a satellite in its orbit. What
that then gave us was a predicted path for the northerly route and a predicted
path the southerly route," explained Chris McLaughlin, senior vice
president of external affairs at Inmarsat. "That’s never been done before;
our engineers came up with it as a unique contribution."
This information was relayed to Malaysian
officials by 12 March, but Malaysia's government did not publicly acknowledge
it until 15 March, according to the Wall Street Journal. Malaysia began to
redirect the search effort that day, to focus on the areas the information
described. However, some officials involved with the probe warned that the lost
days and wasted resources could impede the investigation.
Meanwhile, Inmarsat's engineers carried out
further analysis of the pings and came up with a much more detailed Doppler
effect model for the northern and southern paths. By comparing these models
with the trajectory of other aircraft on similar routes, they were able to
establish an "extraordinary matching" between Inmarsat's predicted
path to the south and the readings from other planes on that route.
"By yesterday they were able to definitively
say that the plane had undoubtedly taken the southern route," said
McLaughlin.
These pings from the satellite – along with
assumptions about the plane’s speed – helped Australia and the US National
Transportation Safety Board to narrow down the search area to just 3 per cent
of the southern corridor on 18 March.
"We worked out where the last ping was, and
we knew that the plane must have run out of fuel before the next automated
ping, but we didn't know what speed the aircraft was flying at – we assumed
about 450 knots," said McLaughlin. "We can’t know when the fuel
actually ran out, we can’t know whether the plane plunged or glided, and we
can’t know whether the plane at the end of the time in the air was flying more
slowly because it was on fumes."
Inmarsat passed the relevant analysis to the UK
Air Accidents Investigation Branch (AAIB) yesterday. The cause of the crash
remains a mystery.
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