(CNN) — A drone submerged Friday in the Indian Ocean for its fifth trip in search of the missing Malaysian plane as relatives of the people who were aboard the jetliner when it disappeared from radar nearly six weeks ago pressed for answers.
The relatives have drawn up 26 questions that they want addressed by a delegation of Malaysian officials who are to meet with them next week in Beijing. Most of the 239 passengers and crew who were aboard Malaysia Airlines Flight 370 were Chinese.
Among their questions: What’s in the flight’s log book? Can they review the jet’s maintenance records? Can they listen to recordings of the Boeing 777 pilot’s conversations with air traffic controllers just before contact was lost?
Malaysia’s acting transport minister, Hishammuddin Hussein, has defended his government’s handling of the operation and accused members of the news media of focusing on the Chinese families. He said relatives of passengers and crew from other nations represented have not had problems.
“The most difficult part of any investigation of this nature is having to deal with the families,” he said.
As the questions mounted, the Bluefin-21 was scanning the floor of the southern Indian Ocean. Authorities said the probe had scanned 42 square miles (110 square kilometers) without making any “contacts of interest.”
The first four dives discovered “no debris or aircraft wreckage,” said Phoenix International Holdings, which owns and operates the equipment under a contract with the U.S. Navy.
A single dive takes 24 hours to complete: two hours to submerge to near the ocean floor, 16 hours to map the seabed, two hours to ascend to the surface and four hours to download the images.
The probe typically can search no deeper than about 14,764 feet (4,500 meters), but Bluefin operators said they can reprogram it to reach 16,404 feet (5,000 meters) — beyond the search area’s maximum depth of about 15,100 feet (4,600 meters).
But searchers seemed to be preparing for a long slog Thursday. A prolonged undersea search by private contractors could cost a “ballpark rough estimate” of $234 million, said Martin Dolan, Australia’s top transport official.
More underwater probes?
Hishammuddin tweeted Friday that authorities are looking at deploying more unmanned underwater probes.
Officials might consider searching along a large portion of sea highlighted by a partial digital “handshake” between the jetliner and an Inmarsat PLC satellite, Dolan said.
That arc of sea is more than 370 miles long and 30 miles wide.
A new setback
Preliminary analysis of an oil sample collected 3.4 miles (5.5 kilometers) from where a ping was detected shows that it is neither aircraft engine oil nor hydraulic fluid, Australia’s Joint Agency Coordination Centre said Thursday.
Malaysia Airlines Flight 370 vanished on March 8 after taking off from Kuala Lumpur, Malaysia, bound for Beijing.
With no debris found and no possible pings from the plane’s “black boxes” detected in more than a week, officials have shifted the focus underwater.
Though air and sea surface searches continued Friday across three areas northwest of Perth, Australia, such searches are probably nearing an end, officials said.
By Faith Karimi, CNN
CNN’s Ivan Watson, Brian Todd, Elizabeth Joseph, Erin Burnett and Steve Almasy contributed to this report.
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