AirAsia captain left seat to fix computer problem before jet lost control

The captain of the AirAsia jet that crashed into the
sea in December was out of his seat conducting an
unorthodox procedure when his co-pilot apparently
lost control, two people familiar with the
investigation said.
Details emerging of the final moments of Flight
QZ8501 are likely to focus attention partly on
maintenance, procedures and training, though
Indonesian officials have said that it is too early to
draw any firm conclusions.
The Airbus A320 jet plunged into the Java Sea
while en route from Surabaya, Indonesia, to
Singapore on 28 December, killing all 162 people
on board.
It had been suffering maintenance faults with a
flight control computer for more than a week, and
one person familiar with the matter said the captain
had flown the same faulty aircraft just days before
the crash.
More on this topic
AirAsia pilots may have turned off plane computer
system before crash, report claims
AirAsia said it would not comment while the matter
was under investigation by the National
Transportation Safety Committee (NTSC) of
Indonesia .
Reuters reported this week that maintenance
problems on the flight augmentation computer
(FAC), and the way the pilots reacted to them, were
at the heart of the investigation.
After trying to reset this device, pilots pulled a
circuit-breaker to cut its power, Bloomberg News
reported on Friday.
People familiar with the matter told Reuters it was
the Indonesian captain Iriyanto who took this step,
rather than his less experienced French co-pilot
Remy Plesel, who was flying the plane .
The outage would not directly upset the aircraft but
would remove flight envelope protection, which
prevents a pilot from taking a plane beyond its
safety limits, leaving the junior pilot to fly the jet
manually in delicate high altitude conditions.
The decision to cut off the FAC has surprised
experts because the usual procedure for resetting it
is to press a button on the overhead panel.
“You can reset the FAC, but to cut all power to it is
very unusual,” said one A320 pilot, who declined
to be identified. “You don’t pull the circuit breaker
unless it is an absolute emergency. I don’t know if
there was one in this case, but it is very unusual.”
It is also significant because to pull the circuit
breaker the captain had to get out of his seat.
The circuit breakers are on a panel behind the co-
pilot and hard or impossible to reach from the
captain’s seat on the left of the cockpit, according
to two experienced pilots.
Shortly afterwards the junior pilot pulled the plane
into a sharp climb from which investigators have
said it stalled or lost lift.
“It appears he was surprised or startled by this,”
said a person familiar with the investigation,
referring to the decision to cut power to the
affected computer.
The captain eventually resumed control, but a
person familiar with the matter said he was not in
a position to intervene immediately to recover the
aircraft from its upset.
Data already published on the plane’s trajectory
suggest it may have been difficult for someone to
move around the cockpit in an upward-tilting and
by then possibly unstable aircraft, but there is so
far no confirmation of the cockpit movements.
“The co-pilot pulled the plane up, and by the time
the captain regained the controls it was too late,”
one of the people familiar with the investigation
said.
Tatang Kurniadi, chief of Indonesia’s NTSC, told
Reuters there had been no delay in the captain
resuming control but declined further comment.
Airbus declined to comment.
Lawyers for the family of the French co-pilot say
they have filed a lawsuit against AirAsia in Paris
for “endangering the lives of others” by flying the
route without official authorisation on that day.
Investigators have said the accident was not
related to the permit issue.
AirAsia did not immediately respond to requests
for comment on the lawsuit.
Although more is becoming known about the chain
of events, people familiar with the investigation
warned against making assumptions on the
accident’s cause, which needed more analysis.
Safety experts say air crashes are most often
caused by a chain of events, each of which is
necessary but not sufficient to explain the
underlying causes of the accident.