Q. and A. on the Disappearance of Malaysia Airlines Flight MH370
The
disappearance of Malaysia Airlines Flight MH370 has left investigators,
aviation experts and the authorities in several countries at a loss to
explain what happened. As the search and inquiry continue, Matthew L.
Wald, a correspondent for The New York Times, answers a few basic
questions:
Q. How could a Boeing 777 simply vanish? Aren’t they always tracked by radar or satellites?
A. Radar
coverage is not universal, especially over water. In areas without
radar, pilots are generally required to radio in their positions at
fixed intervals, mostly to assure that air traffic controllers can keep
aircraft out of one another’s way. Between intervals, something could go
wrong.
Planes like the 777 also have automatic systems that send out data on engine performance and other technical functions. Those signals go to a maintenance base, not to air traffic control. Air France used those signals to help determine what happened when its Flight 447 disappeared over the equatorial Atlantic. Investigators may be doing something similar in Kuala Lumpur.
Q. Plane
crashes most often happen on landing or takeoff, but this flight
vanished almost an hour after takeoff when it was cruising. What could
cause a plane to crash at that point in a flight?
A. In
three crashes at sea in the last few years, the aircraft’s
speed-sensing systems have malfunctioned. In two of those cases, crews
failed to diagnose and cope with the problem. (In the third, there was
probably nothing they could have done.) A deliberate act by a pilot,
terrorism or an attack in the cockpit could be other causes.
Q. Shouldn’t the signals from transponders or “black boxes” have pinpointed the aircraft by now?
A. If
the black boxes are in water, “pingers,” which emit a tone, are
activated. But these are audible only in a limited area. And the plane
may not be in the water.
Q. Why would the authorities not have found debris after so many hours of searching?
A. They
may not be looking in the right place. The plane flies at 10 miles a
minute, and no one knows exactly when it crashed, or whether it departed
its assigned track before doing so.
Q. Are there any signs that terrorism might have been involved?
A. No group is known to have claimed to have destroyed the plane. Beyond that, not enough is known to speculate.
Q. If the plane had a major malfunction, wouldn’t the pilots have called for help and sent distress signals?
A. Pilots
have a mantra for setting priorities in an emergency: aviate, navigate,
communicate. The first priority is to fly the airplane. Telling air
traffic controllers on the ground what is going on comes third, since
doing so is unlikely to instantly yield any help with the crisis in the
cockpit, whatever it may be. If the pilots are fighting to keep the
plane aloft, they may not have time to use the radio.
Q. Could one of the pilots have crashed the plane deliberately?
A. It’s been known to happen: The crashes of an EgyptAir flight from
Kennedy International Airport in 1999 and a SilkAir flight in Indonesia
in 1997 were attributed to intentional acts by cockpit crew members.
But nothing is yet known publicly to suggest that that happened on the
Malaysia Airlines flight.
Q. Have other planes disappeared in this way in recent years?
A.
There is no record of big planes simply disappearing, though they may
take some time to find. A few pieces of debris from Air France Flight
447 were spotted floating in the Atlantic the day after the plane
crashed in June 2009, but it took five days to find most of the
wreckage. Small aircraft may be missing for much longer if they go down
in remote areas. Steve Fossett, the daredevil adventurer who flew around
the world solo in a plane and set records in a balloon, took off in his
private plane in Nevada on Sept. 3, 2007, and his remains were found in
October 2008.
Source : The New York Times
