Wings Magazine

Ship detects black box signals: MH370

April 7, 2014, Perth, Aus. - An Australian ship detected two distinct, long-lasting sounds underwater that are consistent with the pings from aircraft black boxes in a major break in the month-long hunt for the missing Malaysia Airlines jet, the search coordinator said Monday.

April 7, 2014  By The Associated Press

Navy specialists were urgently trying to pick up the signal again so
they can triangulate its position and go to the next step of sending an
unmanned miniature submarine into the depths to try to identify plane


Confirmation that the signals picked up by the Australian navy ship
Ocean Shield belong to Flight 370's black boxes could take days, but the
discovery offers "a most promising lead" yet, said Angus Houston, the
head of a joint agency coordinating the multinational search. They were
stronger and lasted longer than faint signals a Chinese ship reported
hearing farther south in the search zone in the remote Indian Ocean.


"Clearly this is a most promising lead, and probably in the search so
far, it's probably the best information that we have had," Houston said
at a news conference. "We've got a visual indication on a screen and
we've also got an audible signal — and the audible signal sounds to me
just like an emergency locator beacon."


After a month-long search for answers filled with dead ends, Monday's
news brought fresh hope given that the two black boxes, which contain
flight data and cockpit voice recordings, are the key
to unravelling exactly what happened to Flight 370 and why.


In Kuala Lumpur, Malaysian Defence Minister Hishammudin Hussein told
reporters that in light of the new information, "We are cautiously
hopeful that there will be a positive development in the next few days,
if not hours."


Little time is left to locate the devices, which have beacons that
emit "pings" so they can be more easily found. The beacons' batteries
last only about a month — and Tuesday marks exactly one month since the
plane disappeared during a flight from Kuala Lumpur to Beijing with 239
people on board.


The Ocean Shield, which is carrying high-tech sound detectors from
the U.S. Navy, picked up two separate signals late Saturday night and
early Sunday morning in seas far off the west Australian coast that
search crews have been crisscrossing for weeks. The first signal lasted
two hours and 20 minutes before it was lost. The ship then turned around
and picked up a signal again — this time recording two distinct
"pinger returns" that lasted 13 minutes, Houston said.


"Significantly, this would be consistent with transmissions from both
the flight data recorder and the cockpit voice recorder," Houston said.


Still, Houston cautioned that it was too early to say the transmissions were coming from the missing jet.


"I would want more confirmation before we say this is it," he said.
"Without wreckage, we can't say it's definitely here. We've got to go
down and have a look."


The ping locator is pulled behind the ship at a depth of
3 kilometres and is designed to detect signals at a range of
1.8 kilometres, meaning it would need to be almost on top of the black
boxes to detect them if they were on the ocean floor, which is about
4.5 kilometres deep.


"It's like playing hot and cold when you're searching for something
and someone's telling you you're getting warmer and warmer and warmer,"
U.S. Navy Capt. Mark Matthews said. "When you're right on top of it you
get a good return."

The black boxes normally emit a frequency of 37.5 kilohertz, and the
signals picked up by the Ocean Shield were both 33.3 kilohertz, he said.
But the manufacturer indicated the frequency of black boxes can drift
in older equipment.


The Ocean Shield was slowly canvassing a small area trying to find
the signal again, though that could take another day, Matthews said.

If they pick up the signal again, the crew will launch an underwater
vehicle to investigate, he said. The Bluefin 21 autonomous sub can
create a sonar map of the area to chart where the debris may lie on the
sea floor. If it maps out a debris field, the crew will replace the
sonar system with a camera unit to photograph any wreckage.


That may prove tricky because the water depth is right at the limits of the sub's capability.


"It could take some days before the information is available to
establish whether these detections can be confirmed as being from
MH370," Houston said. "In very deep oceanic water, nothing happens


Geoff Dell, discipline leader of accident investigation at Central
Queensland University in Australia, said it would be "coincidental in
the extreme" for the sounds to have come from anything other than an
aircraft's black box.


"If they have a got a legitimate signal, and it's not from one of the
other vessels or something, you would have to say they are within a
bull's roar," he said. "There's still a chance that it's a spurious
signal that's coming from somewhere else and they are chasing a ghost,
but it certainly is encouraging that they've found something to suggest
they are in the right spot."


Meanwhile, the British ship HMS Echo, was using sophisticated
sound-locating equipment to try to determine whether two separate sounds
heard by a Chinese ship about 555 kilometers away from the Ocean Shield
were related to the plane. The patrol vessel Haixun 01 detected a brief
"pulse signal" on Friday and a second signal on Saturday.


The crew of the Chinese ship reportedly picked up the signals using a
sonar device called a hydrophone dangled over the side of a small boat —
something experts said was technically possible but extremely unlikely.
The equipment aboard the British and Australian ships is dragged slowly
behind each vessel over long distances and is considered far more


The search effort continued on the ocean surface Monday. Twelve
planes and 14 ships searched three designated zones, one of which
overlaps with the Ocean Shield's underwater search. All of the previous
surface searches have found only fishing equipment or other sea trash
floating in the water.


Stories continue below