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Missing Malaysia airline might never be found

Published

11 years ago

March 14, 2014

Sometimes, the crash site is never found.
In 1972 a Pan Alaska Airways flight with one pilot and three
passengers took off from Anchorage bound for Juneau, planning to fly
the route under visual flight rules despite bad weather conditions.
After one last contact with air traffic controllers, the Cessna was on
its way. The plane never reached Juneau. The flight had two
congressmen on board — Hale Boggs of Louisiana and Nicholas
Begich of Alaska.
The search for the missing aircraft was intense, encompassing 325,000
square miles of land and sea, with 3,600 flight hours used to look for
the wreckage. But after 39 days, the search was called off. A
National Transportation Safety Board report acknowledged that the
cause might never be known.
In the case of Malaysia Flight 370, a Boeing 777
missing since Saturday, a search of an area captured by
Chinese satellite images that seemed to pinpoint the
crash site turned up nothing. Such images are rare, and
typically, when a plane goes down in a remote area with
no witnesses, one of the most crucial tools available to
investigators is radar.
“It’s very important,” said John Griffin II, an
associate professor at Embry-Riddle Aeronautical
University who specializes in air traffic control. “There
are basically two ways to find a plane — radar and pilot
communication.”
Radar can take two forms. One is primary radar, what’s sometimes
called “skinpaint,” that simply reflects off an object. Primary radar
doesn’t give any information about the object it’s tracking. “If you
work at an ATC (Air Traffic Control) facility on an East Coast
flyway, you will pick up flocks of birds,” Griffin said. Primary radar
can also pick up debris that might be raining down from an in-flight
explosion, and in such cases a target that appears as one object
suddenly appears as several objects.
Secondary radar, on the other hand, relies on plane’s
transponder, a device located in the nose of the plane.
The transponder broadcasts a signal to air traffic
controllers that identifies the flight and its altitude.
Secondary radar is more than just a blip on a radar
screen; it tells the controllers the valuable information
about the specific aircraft.
Malaysia Flight 370’s transponder stopped broadcasting
about 45 minutes into the flight. At that point, air traffic
controllers in Kuala Lampur had no more contact with
the aircraft. At first, the search area focused on the
plane’s intended flight path, as officials went on the
assumption that the plane did not change course. “Then
they started exploring other possibilities,” Griffin said.
Military radar tracked unidentified targets that could
have been Flight 370 heading west toward the Strait of
Malacca and possibly beyond.
Military radar can cover areas not covered by civilian
air traffic control. But without the plane’s transponder
working, that target tracked by radar is only
“skinpaint,” or the reflection of a dense object. It can’t
identify the plane or give an altitude. And even the
radar can only provide so much information. It’s
possible for a plane to literally fly under the radar
because coverage usually doesn’t go all the way down to
the surface. In that case, a plane could continue
undetected even in areas covered by radar.
In addition to the 1972 Alaska crash, other aircraft
have gone missing without a trace. In 1962, a Flying
Tiger Line Lockheed Constellation operating as a
military transport disappeared over the Pacific after
taking off from Guam. The recovery operation included
48 aircraft, but no sign of the plane was ever found.