The missing jet
Relatives of the people on board
A jet flying from Surabaya, Indonesia, to Singapore with 162 people
aboard lost contact with air traffic control over the Java Sea about an hour
before it was to land and is missing, AirAsia Indonesia officials said Sunday.
Flight QZ8501 took off at about 5:35 a.m. Sunday local time from Juanda
International Airport and lost contact with air traffic control at about 7:24
a.m., the airline said on its Facebook page. The time in Surabaya is 12 hours
ahead of Eastern Standard Time; Singapore is 13 hours ahead of ET.
"We don't dare to presume what has happened except that it has lost
contact." Djoko Murjatmodjo, Indonesia's acting director general of
transportation, told reporters. He said the last contact between pilot and the
air traffic control was at 6.13 a.m. local time when the pilot asked to avoid a
cloud bank by turning left and going higher to 34,000 feet.
Flight QZ8501 gave no distress signal, he said.
Another
missing plane: How airlines use tracking technology
As another plane has gone missing in Southeast Asia, attention is paid
to the tracking systems that commercial airlines use. AirAsia Flight QZ8501,
carrying 162 people, lost contact with air traffic control.
Planes typically relay maintenance information in flight to their
manufacturers or airlines. This data can also help track a lost plane like Air
France Flight 447, which crashed in the Atlantic in 2009.
In the case of Malaysia Airlines Flight 370, the technology at issue is
called ACARS, for Aircraft Communications Addressing and Reporting System. The
system sends different sorts of information between the plane and airlines and
manufacturers on the ground. Depending on the sophistication of the information,
the airline might receive the information itself or rely on the manufacturer to
relay it for a fee.
John Hansman, director of the International Center for Air
Transportation at Massachusetts Institute of Technology, estimates 90% of U.S.
planes have some version of the system because it saves airlines money.
At first, the precise monitoring of when brakes were engaged or when
planes took off or landed helped airlines track personnel costs more
accurately, Hansman said. Maintenance reports can show when an engine is
running hotter than usual, which signals wear, he said.
"The reason why people do this is because if something breaks in
flight, if maintenance gets the message they can actually be at the landing
point with the replacement part and fix the airplane and turn it around
quickly," Hansman said.
In general, the messages can be sent cheaply over land by VHF signal,
like the Apollo astronauts used, Hansman said. Or they can be sent over water
by satellite, which is a more expensive service to send messages, he said.
The sophistication of the service depends on what the airline would like
to spend. For example, Boeing promotes a service called custom alerting and
analysis, which is available for 777, 747 and 787 aircraft with high-speed
Internet connections. It monitors fuel, flight controls, landing gear,
hydraulic power and communications.
"The major carriers collect it themselves because they have the
capability of processing it and deciphering it and so forth," said David
Greenberg, who worked 27 years at Delta Air Lines and is now an airline
consultant as president of Compass Group. "My understanding is that
Malaysia doesn't subscribe to the Boeing program and that they collect the data
for their own use."
While Malaysia Airlines and its manufacturers aren't saying what sort of
service was used on Flight 370, the Airbus A330 in the Air France crash had
sophisticated messaging that reported problems with airspeed and altitude that
helped track down the missing plane.
"In Air France, that's how they knew where to look," Hansman
said.
This missing AirAsia aircraft is an Airbus A320-200.
Breaking: Air Asia Missing with 162 Passengers
Reviewed by Unknown
on
Sunday, December 28, 2014
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