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发帖数: 22064 | 1 http://www.nytimes.com/2014/03/18/world/asia/malaysia-airlines-
By MATTHEW L. WALD and MICHAEL S. SCHMIDT
WASHINGTON — The first turn to the west that diverted the missing Malaysia
Airlines plane from its planned flight path from Kuala Lumpur to Beijing was
carried out through a computer system that was most likely programmed by
someone in the plane’s cockpit who was knowledgeable about airplane systems
, according to senior American officials.
Instead of manually operating the plane’s controls, whoever altered Flight
370’s path typed seven or eight keystrokes into a computer on a knee-high
pedestal between the captain and the first officer, according to officials.
The Flight Management System, as the computer is known, directs the plane
from point to point specified in the flight plan submitted before a flight.
It is not clear whether the plane’s path was reprogrammed before or after
it took off.
The fact that the turn away from Beijing was programmed into the computer
has reinforced the belief of investigators — first voiced by Malaysian
officials — that the plane was deliberately diverted and that foul play was
involved. It has also increased their focus on the plane’s captain and
first officer.
Prime Minister Najib Razak of Malaysia told reporters on Saturday that his
government believed that the plane had been diverted because its transponder
and other communications devices had been manually turned off several
minutes apart. American officials were told of the new information over the
weekend.
But the Malaysian authorities on Monday reversed themselves on the sequence
of events they believe took place on the plane in the crucial minutes before
ground controllers lost contact with it early on March 8. They said it was
the plane’s first officer — the co-pilot — who was the last person in the
cockpit to speak to ground control. And they withdrew their assertion that
another automated system on the plane, the Aircraft Communications
Addressing and Reporting System, or Acars, had already been disabled when
the co-pilot spoke.
Flight 370’s Flight Management System reported its status to the Acars,
which in turn transmitted information back to a maintenance base, according
to an American official. This shows that the reprogramming happened before
Acars stopped working. The Acars ceased to function about the same time that
oral radio contact was lost and the airplane’s transponder also stopped,
fueling suspicions that foul play was involved in the plane’s disappearance.
Investigators are scrutinizing radar tapes from when the plane first
departed Kuala Lumpur because they believe the tapes will show that after
the plane first changed its course, it passed through several pre-
established “waypoints,” which are like virtual mile markers in the sky.
That would suggest that the plane was under control of a knowledgeable pilot
, because passing through those points without using the computer would have
been unlikely.
According to investigators, it appears that a waypoint was added to the
planned route. Pilots do that in the ordinary course of flying if air
traffic controllers tell them to take a different route, to avoid weather or
traffic. But in this case, the waypoint was far off the path to Beijing.
Whoever changed the plane’s course would have had to be familiar with
Boeing aircraft, though not necessarily the 777 — the type of plane that
disappeared. American officials and aviation experts said it was far-fetched
to believe that a passenger could have reprogrammed the Flight Management
System.
Normal procedure is to key in a five-letter code — gibberish to non-
aviators — that is the name of a waypoint. A normal flight plan consists of
a series of such waypoints, ending in the destination airport. For an
ordinary flight, waypoints can be entered manually or uploaded into the F.M.
S. by the airline.
One of the pilots keys in a waypoint on a separate screen known as a
scratchpad, and after confirming that it has no typographical errors, pushes
another button to move it into the sequence already in the flight plan.
Normal practice is to orally confirm the waypoint with the other pilot, then
push another button to instruct the airplane to go there. With the change
in course, the plane would bank at a comfortable angle, around 20 degrees,
and make the turn. Passengers would not feel anything unusual.
ABC News reported on Sunday that the programmed turn had led investigators
to believe that it was being controlled by the pilot or hijackers.
One American safety expert, John Cox, a former airline union safety official
, said that someone taking such pains to divert the plane does not fit the
pattern of past cases when pilots intentionally crashed and killed everyone
on board.
“There’s an inconsistency in what we’ve seen historically,” he said,
comparing the disappearance of Flight 370 with two murder-suicides, on
anEgyptair flight off Nantucket Island in 1999 and a SilkAir jet in
Indonesia in 1997. In those crashes, he said, the pilot involved simply
pushed the nose of the plane down and flew into the water. The authorities
searched the homes of the pilots in Kuala Lumpur on Saturday, seizing a
flight simulator that one of them had in his home.
In an effort to determine whether the pilot had practiced taking down the
plane, the authorities have reassembled the simulator for experts to examine
. American investigators would like access to the flight simulator and any
other electronic information seized from the pilots, but as of Monday night
they had not been given access to those materials.
Meanwhile, as the search for the missing Boeing 777 jet stretched into a
10th day, two of the nations helping in the hunt, Australia and Indonesia,
agreed to divide between them a vast area of the southeastern Indian Ocean,
with Indonesia focusing on equatorial waters and Australia beginning to
search farther south for traces of the aircraft. To the north, China and
Kazakhstan checked their radar records and tried to figure out whether the
jet could have landed somewhere on their soil. |
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