Hunt for Jet Switches to Visual Search as Radar Empty

Australian authorities said planes scouring the southern Indian Ocean for the missing Malaysian airliner are switching to a visual search of the region after radar scans came up empty yesterday.

“Although this search area is much smaller than what we started with, it nonetheless is a big area when you’re looking out the window and trying to see something by eye,” said John Young, general manager of emergency response at the Australian Maritime Safety Authority. “We may have to do this a few times to be confident about the coverage of this search area.”

Australia, the U.S. and New Zealand resumed their search today by sending aircraft to search a region 2,500 kilometers (1,550 miles) southwest of Perth. China is deploying at least seven ships, including an icebreaker and three naval vessels, state-run Xinhua News Agency said.

After satellite photographs of objects in the southern Indian Ocean kindled hopes of a breakthrough yesterday, planes sent to the area haven’t been able to locate any wreckage. As the longest search for a passenger jet stretched into its 14th day, Malaysia’s Acting Transport Minister Hishammuddin Hussein said: “This is going to be a long haul.”

Satellite Analysis

Malaysian Airline System Bhd. Flight 370 may have cruised steadily across the Ocean after diverting from its scheduled route to Beijing from Kuala Lumpur, according to an analysis of satellite pings. It’s the clearest idea yet on how investigators pinpointed a search zone.

Engineers at Inmarsat Plc, whose satellite picked up the pings, plotted seven positions for the Boeing Co. 777-200ER on March 8, Chris McLaughlin, a company spokesman, said in an interview. The plane flew steadily away from the satellite over the equator while pinging, McLaughlin said. Malaysia needs to verify that information, Azharuddin Abdul Rahman, the chief of the nation’s civil aviation, said in Kuala Lumpur.

The data helped investigators conclude that the most logical path was progressively either north or south. U.S. investigators have focused the search to the south and Australia is leading the efforts to scour the southern Indian Ocean for the jet that vanished March 8 with 239 people on board.

Probable Path

When officials estimated the plane was flying at or near its cruising speed of more than 500 miles (800 kilometers) an hour, it produced a probable path the engineers were “very confident” about, McLaughlin said.

The engineers don’t know the plane’s track for certain because the satellite pings can only be used to estimate an arc along the earth’s surface where it would have been, he said.

“You can assume the tracking was based on what the autopilot was set for on the 777,” he said.

If the Inmarsat estimates are accurate, it would have been impossible for the plane to have landed before its satellite transmitter sent the final ping at 8:11 a.m., almost seven hours after its last known position as it left Malaysian airspace, according to McLaughlin’s account. Because the 777 burns more fuel at lower altitude, it also suggests the plane remained at cruising altitude.

The plane was flying at 542 miles an hour at 35,000 feet (10,668 meters) at 1:21 a.m. when its transponder stopped functioning and it disappeared from Malaysian’s civilian radar system, according to FlightRadar24, a flight-tracking company.

India Search

The engineers at Inmarsat were able to validate their estimates of the plane’s location by matching its position at 1:07 a.m., when it sent a burst of data through its Aircraft Communications and Reporting System, McLaughlin said. That final transmission on Acars included a GPS position that was used to calibrate the other estimates, he said.

The Inmarsat analysis is consistent with details suggesting that, at least initially, the path was commanded from the cockpit, John Cox, president of Washington-based Safety Operating Systems, said in an interview. It still doesn’t answer what may have happened to the plane and what led it to fly for so long, he said.

Planes today resumed the hunt for the missing jet after an initial foray yesterday failed to find two objects seen in satellite images. The weather and visibility were poor and aircraft radar searches made no sightings, said Young. A piece as big as 24 meters, and a second one as big as 5 meters, were spotted in images taken March 16.

India meanwhile continued its search, sending two ships west of the Andaman and Nicobar Islands and a P-8I aircraft southeast toward Sumatra, military spokesman Harmit Singh said in a text message. India sent another P-8I and a C-130J to Kuala Lumpur as additional resources for Malaysia, he said.

Not Nice

“It’s about the most inaccessible spot you could imagine on the face of the earth,” Australian Prime Minister Tony Abbott said today, referring to the search area southwest of Perth.

While images of the ocean bottom in the area suggest a flat plain, there may be features that no one’s mapped yet, she said, citing a 40-kilometer long undersea canyon less than 200 kilometers off Australia’s north-west coast that wasn’t discovered until 2010.

“It isn’t known as a nice place to work,” said Anya Waite, a professor of oceanography at the University of Western Australia’s Oceans Institute. “It’s not for the faint hearted to go down there, let alone look for a needle in a haystack. The winds cycle around the bottom of the world, so it can gather energy in a way that almost no other ocean does.”

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