The lost Malaysia airline(update)

STORY HIGHLIGHTS
The batteries the power pings from the data
and voice recorders last for 30 days
"The odds of finding the pinger are very
slim," an ocean search specialist says
Recent developments shed some light on
early part of flight, but not where plane
went next
The total search area is roughly the size of
the continental United States

A ticking clock. A widening search.
The box containing the flight-data and
cockpit-voice recorders of missing Malaysia
Airlines Flight 370 has batteries designed to
keep it sending out pings for 30 days.
The search is now in its 12th day, covering a
total area roughly the size of the continental
United States. That leaves 18 days until the
batteries are expected to run out.
Investigators hope the recorders may reveal
vital information about why the passenger jet
carrying 239 people veered dramatically off
course and disappeared from radar screens.
But they have to find them first.
Searchers from at least 26 countries have a
formidable task in pinpointing the plane's
location somewhere along two vast arcs, one
stretching deep into the Asian landmass, the
other far out into the Indian Ocean.
"The odds of finding the pinger are very slim,"
said Rob McCallum, an ocean search
specialist. "Even when you know roughly where
the target is, it can be very tricky to find the
pinger. They have a very limited range."
Some of the nations involved in the hunt are
deploying an impressive array of technology,
including satellites and high-tech submarine-
hunting planes, as they try to narrow the
search area.
They're also trawling through existing radar
and satellite data for clues.
Small details emerge
Much of what has emerged in recent days has
filled in a few more details about the early
part of the missing Boeing 777-200's flight.
But clear information on what went on in the
cockpit and where exactly the errant jet went
after it vanished from Malaysian military radar
remains frustratingly elusive.
On Tuesday, for example, a law enforcement
official told CNN that the aircraft's first major
change of course was almost certainly
programmed by somebody in the cockpit. The
change was entered into the plane's system at
least 12 minutes before a person in the
cockpit, believed to be the co-pilot, signed off
to air traffic controllers.
But that disclosure only left more questions
about the reason behind the reprogrammed
flight path.
Some experts said the change in direction
could have been part of an alternate flight
plan programmed in advance in case of
emergency; others suggested it could show
something more nefarious was afoot.
The Thai military, meanwhile, said it had
spotted the plane turning west toward the
Strait of Malacca early on March 8. That
supports the analysis of Malaysian military
radar that has the plane flying out over the
Strait of Malacca and into the Indian Ocean.
But it didn't make it any clearer where the
plane went next. Authorities say information
from satellites suggests the plane kept flying
for about six hours after it was last detected
by Malaysian military radar.
Who was at the controls?
Malaysian authorities, who are coordinating
the search, say the available evidence
suggests the missing plane flew off course in
a deliberate act by someone who knew what
they were doing.
Figuring out who that might be has so far left
investigators stumped.
Particular attention has focused on the pilot
and first officer on Flight 370, but authorities
are yet to come up with any evidence
explaining why either of them would have
taken the jetliner off course.
And some experts have warned against hastily
jumping to conclusions about the role of the
pilots.
"I've worked on many cases were the pilots
were suspect, and it turned out to be a
mechanical and horrible problem," said Mary
Schiavo, a CNN aviation analyst and former
inspector general for the U.S. Department of
Transportation. "And I have a saying myself:
Sometimes an erratic flight path is heroism,
not terrorism
China says it has found nothing suspicious
during background checks on its citizens on
the flight -- a large majority of the plane's
passengers.
Searchers face deep ocean
Malaysian Transport Minister Hishammuddin
Hussein, the country's public face of the
search efforts, has repeatedly said at news
conferences that little is likely to be
established about the mysterious flight until
the plane is found.
But in the Indian Ocean, where Australia and
Indonesia have taken the lead in the hunt,
some of the depths searchers are dealing with
are significant.
The Bay of Bengal, for example, which lies
between Myanmar and India, has depths of
between about 4,000 and 7,000 meters
(13,000 feet and 23,000 feet), according to
McCallum.
Wreckage and bodies of passengers from Air
France Flight 447, which crashed into the
Atlantic Ocean in 2009, were found at depths
of around 12,000 feet by unmanned
submarines.
It took four searches over the course of nearly
two years to locate the bulk of the wreckage
and the majority of the bodies of the 228
people on board Flight 447. It took even
longer to establish the cause of the disaster.
Right now, authorities don't even know for
sure if the missing Malaysian plane crashed or
landed -- or where.
CNN has talked to more than half a dozen
U.S. military and intelligence officials who
emphasize that while no one knows what
happened to the plane, it is more logical to
conclude it crashed into the Indian Ocean.
The officials say there is no evidence that any
U.S. satellite data registered an unknown
aircraft in any of the Asian countries along the
path the plane may have taken. According to
these officials, it is overwhelmingly likely if the
plane had crashed on land, there would be
some evidence of that, and if it had landed,
someone would have seen it.

Source:CNN news