Answers elusive in Air France crash
As more bodies are pulled from the
sea, few answers are forthcoming as to the cause of last week's Air France A330
crash off the Brazilian coast.
Modern
aircraft are robust machines with high levels of redundancy built in, and
rarely fall out of the skies due to a single systems failure.
When
they tragically occur, accidents are invariably the result of a complex
sequence of events that come together and conspire to doom an airliner, despite
the best efforts of those in control to avert a disaster.
Seven
days after Air France
flight AF 447 disappeared, we know precious little as to what occurred aboard
the airliner that night.
We
have been told that weather in the region was poor at the time of the crash,
but aircraft are designed to withstand all but the most destructive forces that
nature can throw at them.
We
know that in the few precious minutes before the jet plunged towards the ocean,
automated monitoring systems began to transmit a sequence of 24 short error
messages.
Although
they indicated that critical systems were beginning to shut down, we have no
understanding as to what precipitated this flurry of data traffic.
We
understand that the auto-pilot was disengaged at the time these error messages
were sent.
But
we have no clues as to whether this was an un-commanded disengagement prompted
by some other systems failure, or whether the pilot took control in a valiant
but ultimately failed attempt to rescue his aircraft.
Black boxes key
These
slivers of information are the first pieces in a gigantic jigsaw puzzle that
will take significantly longer than might otherwise have been the case had the
airliner come down in a more accessible location.
With
a wreckage field strewn across a swathe of the Atlantic Ocean some 1,000km (600
miles) north-east of Brazil's Fernando de Noronha islands, it is one of the
most difficult areas in which to conduct a search and recovery mission.
The
discoveries of human remains and some wreckage over the weekend may yield
further important clues as to the cause of the crash.
But
it is imperative that the larger sections of the aircraft be discovered as
well, and most importantly, the so-called black boxes are found and recovered
for analysis.
This
is easier said than done. The nature of the crash may mean that debris is
scattered over a very wide area and currents could have carried key remains a
substantial distance from the point of impact.
Sophisticated
sonar equipment is being deployed to positively identify the submersed wreckage
field, and listen out for sonar beacons we hope are still attached to the
flight recorders.
But
the clock is ticking down since these beacons will only operate to a maximum of
30 days. Beyond this time, the recorders may be lost forever in the depths of
the ocean.
We
have also been told that speed sensors aboard the aircraft may have
malfunctioned and this is a known problem specific to the A330 and A340 family
of aircraft.
Sensors
aboard this flight had not been replaced as per a recommendation by Airbus, the
aircraft manufacturer.
It
is important to stress that this information represents only one more piece of
the jigsaw. This was a recommendation and not a safety-critical requirement.
There
are many other ways to determine speed and it would be dangerous at this stage
to draw conclusions from this revelation.
Source:
BBC World News