32 Vol. 9 / No. 12/ December/January 2017/18 Global Aviator
it is procedure for them to check each
other’s work in order to avoid mistakes.
Could the possibility of
fatigue maybe have played a role
that lead up to the incident?
The ATSB report said that fatigue
would have been an unlikely factor,
however according to the captain (who
told the media), he was sleep deprived.
The captain of Flight 407 had slept
for only 6 hours during the course of
24 hours before the accident, while
in that same 24 hour period; the first
officer had slept only 8 hours.
According to the Flight Operations
Manual, there is a maximum limitation
of a 100 flying hours in a 28-day period.
At the time of the incident none of the
crew members exceeded the time limit.
According to a former Emirates
captain, he had once made a similar
mistake as a result of fatigue, but
luckily in that case it was picked
up before the airplane took off.
It remains a fact that fatigue
remains an unresolved issue, but
different airlines have different rules.
We now know that human
error was in fact the cause of
the accident, but here are a few
contributing safety factors:- Perhaps the crew did not complete
all of the tasks in the standard
operating procedure, during
the pre-departure phase, which
would have contributed to
them not detecting the error. - The captain could have been
distracted while checking the
take-off performance figures in
the electronic flight bag, which
would have resulted in him
not detecting the mistake of
the incorrect take-off weight. - The first officer accidentally entered
the incorrect take-off weight, to
calculate the take-off performance
parameters for the flight.- While the crew was busy with the
load sheet confirmation procedure,
the first officer called out 362.9
tonnes as the FLEX take-off weight,
instead of the correct 262.9 tonnes
recorded on the master flight
plan. By doing so, it removed the
opportunity where the captain
could have detected the mistake. - Also during the load sheet
confirmation procedure, the first
officer changed the first digit of the
FLEX take-off weight, he could have
been under the impression that it
had been transcribed incorrectly.
Therefore another opportunity was
lost for the crew to detect the error.- The crew was exposed to large
variations in take-off weights and
take-off performance parameters,
due to their mixed fleet flying
routines. This influenced their
ability to form a “reasonable”
expectation of the calculated take-
off performance parameters.
There have been numerous
similar incidents. In fact flight 407
mirrors an incident involving a
Singapore Airlines 747 in Auckland
in 2003. The pilot of that flight also
mistakenly entered the weight a
100 tonnes lighter, because he was
not given the correct information.
Another similar incident
occurred at Johannesburg on 9
April 2004, when pilots smashed
their airplane through the landing
lights at the end of the runway.
Unfortunately in the case of
Flight 407, both pilots handed in
their resignation after the incident.
After repairs on 1 December
2009, the airplane made its first
revenue flight as flight EK424, it
remained in service operating short
to medium haul international flights
out of Dubai. In October 2014 it was
withdrawn from service and it was
scrapped later that same year.
Due to the fact that the crew
possibly had some difficulty
in recognising the fact that the
incorrect data had been entered,
which resulted in poor take off
performance, Airbus are investigating
the development of software
that can help pilots to recognise
poor performance on take-off.
Also as a result of the accident, a
number of safety actions have been or
are being taken by the operators and
aircraft manufacturer. In addition,
a safety recommendation has been
issued to the United States Federal
Aviation Administration by the
Australian Transport Safety Bureau.
In an effort to minimise similar
future accidents like flight 407,
they have also issued a safety
advisory notice to the International
Air Transport Association and
the Flight Safety Foundation. •
Above: Indicated by point 1,2 and 3 are the
points where the aircraft's tail struck the
ground. The aircraft lost contact with the
ground until point 4 in the clearway due
to a small drop-off. No 5 shows the final
ground contact mark, 148m beyond the
end of the runway.Left: Gear tracks in the grass as a result
of the runway overrun as well as the
damaged localizer antenna.Airline incidents