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.
A member
of the military looked out of a helicopter during a search-and-rescue mission
off the Tho Chu Islands of Vietnam on Monday. Credit Athit
Perawongmetha/Reuters
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.
INDONESIA
The New
York Times
Sources:
Malaysia’s Department of Civil Aviation (search areas); flightradar24.com
(flight path); Malaysia Airlines; GEBCO (water depth)
A. While we know where the last
radio contact was, we do not know how long after that the airplane crashed, so
it is hard to say. A jetliner cruising at 35,000 feet could glide as far as 80
or 90 miles after losing engine power if the pilots still had control.
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.
