LATEST: Australia's Joint Agency Coordination Centre, which is fronting the search, said Wednesday the device looking for the plane on the seabed had scanned some 80 per cent of its target zone without result.
The torpedo-shaped autonomous underwater vehicle called a Bluefin-21 is on mission 10 in the underwater search area, JACC said.
"Bluefin-21 has now completed more than 80 percent of the focused underwater search area.
"No contacts of interest have been found to date."
The device is searching an area at least 4,500 metres (15,000 feet) deep defined by a 10-kilometre (six-mile) radius around a detection of a signal believed to be from the plane's black box heard on April 8.
A visual surface search involving up to 10 military aircraft and 12 ships was also planned for Wednesday, despite suggestions last week that this aspect would be scaled down in coming days.
The visual hunt would cover an area totalling about 37,948 square kilometres (14,650 square miles) some 855 kilometres (530 miles) northwest of Perth, JACC said.
Australia said Wednesday cost was not a concern in the search for Malaysia Airlines Flight MH370, after the mini-sub plumbing the depths of the Indian Ocean for wreckage ended its ninth mission empty-handed.
Australia is leading the multinational search for the Boeing 777 which vanished on March 8 carrying 239 people, and is bearing many of the costs of the mission expected to be the most expensive in aviation history.
"There will be some issues of costs into the future but this is not about costs," Defence Minister David Johnston told reporters in Canberra.
"We want to find this aircraft. We want to say to our friends in Malaysia and China this is not about cost, we are concerned to be seen to be helping them in a most tragic circumstance."
A tropical cyclone heading south over the Indian Ocean caused the air search for a missing Malaysian jetliner to be suspended on Tuesday, as a US submarine drone neared completion of its undersea search without any sign of wreckage.
The daily air and sea sorties have continued for a week since Australian authorities said they would end that component of the search for Malaysia Airlines Flight MH370, which disappeared on March 8 with 239 people on board.
But on Tuesday, hours after authorities said up to 10 military aircraft and 10 ships would join the day's search, they said the air search had been suspended because of poor weather as a result of Tropical Cyclone Jack.
"It has been determined that the current weather conditions are resulting in heavy seas and poor visibility, and would make any air search activities ineffective and potentially hazardous," the Joint Agency Coordination Centre said in a statement.
Nothing found yet
The search for the missing Malaysia flight MH370 has ended yet again on the 45th day without finding anything.
According to a report in CNN, the eighth mission ended Monday, after covering two-third of its intended territory, without discovering any sign of the missing plane.
The Bluefin-21 began its eighth mission on Sunday and surveyed the bottom of the southern Indian Ocean.
It is expected to begin the ninth mission later on Monday.
Ten military aircraft and 11 ships would participate in the day’s search, Australia’s Joint Agency Coordination Centre was quoted as saying in the report.
Meanwhile, a tropical cyclone Jack is circulating northwest of the search area and is likely to increase winds and rains, the report said and added, however, it won't hit directly.
Search enters 'very critical juncture'
The effort to find missing flight MH370 is at a "very critical juncture", Malaysia's transport minister said Saturday as authorities mull whether to reassess a challenging search of the Indian Ocean seabed that has so far found nothing.
"The search for today and tomorrow is at a very critical juncture. So I appeal for everybody around the world to pray and pray hard that we find something to work on," Transport Minister Hishammuddin Hussein said.
Malaysia was already in discussions with private companies on the possible use of more deep-sea vessels if the mini-submarine currently searching the ocean floor fails to make a breakthrough, Hishammuddin added.
Australian officials supervising the search for missing Malaysia Airlines Flight MH370 told Reuters on Saturday that an underwater search for the black box recorder based on "pings" possibly from the device could be completed in five to seven days.
Drone diving to record level in Malaysian plane search
A US Navy deep-sea drone is diving to unprecedented depths to scour a remote stretch of the Indian Ocean floor for a missing Malaysian jetliner as the Malaysian government said it may use more remote control submarines to help with the search.
The Bluefin-21 and its "side scan" sonar has become the focal point of the search 2,000 km (1,200 miles) west of the Australian city of Perth.
Now in its seventh week, the search has centred on a city-sized area where a series of "pings" led authorities to believe the plane's black box may be located. But after almost two weeks without a signal, and long past the black box battery's 30-day life expectancy, authorities have turned to the Bluefin-21.
After the $4 million Bluefin-21's searches were frustrated by an automatic safety mechanism which returns it to the surface when it exceeds a depth of 4.5 km (14,763 feet), authorities have adjusted the mechanism and have sent it as deep as 4,695 metres (15,403 feet), a record.
But hopes that the Bluefin might soon guide searchers to wreckage are dwindling with no sign of the plane after six deployments spanning 133 square kilometres (83 square miles). Footage from the Bluefin's sixth mission was still being analysed, the Joint Agency Coordination Centre said on Saturday.
Malaysian acting Transport Minister Datuk Seri Hishammuddin Hussein said in a Twitter post that the government's Deployment of Assets Committee was considering using more autonomous underwater vehicles. He did not elaborate.
Malaysia, Australia in deal on black box custody
Malaysia and Australia will sign a deal specifying who handles any wreckage from missing flight MH370 that may be recovered, including the crucial "black box" flight data recorders, local media reported Friday.
Malaysia is drafting the agreement "to safeguard both nations from any legal pitfalls that may surface during that (recovery) phase," the New Straits Times reported.
The government hopes the deal can be finalised soon and endorsed in a Cabinet meeting next week. Canberra is studying the memorandum of understanding, it said.
"The MoU spells out exactly who does what and the areas of responsibility," civil aviation chief Azharuddin Abdul Rahman was quoted as saying.
Azharuddin added that Malaysia would lead most of the investigation, with Australia and others helping. Details of the MoU will not be made public, the report said.
Azharuddin and other officials could not immediately be reached by AFP.
The Malaysia Airlines flight carrying 239 people inexplicably veered off course en route from Kuala Lumpur to Beijing on March 8 and is believed to have crashed in the southern Indian Ocean far off western Australia.
But a massive international search has failed to turn up any wreckage so far.
The crisis has brought intense international scrutiny on Malaysia's government, which has been accused by anguished Chinese families and other critics of hiding information and possibly trying to cover up its handling of the situation.
Malaysia's government has rejected such claims, saying it is passing on all it knows promptly. Two-thirds of the passengers were Chinese.
The government-controlled New Straits Times said the Malaysia-Australia deal would address "specific areas" including who will handle the wreckage and the flight data recorders, known as black boxes.
Malaysia's scandal-prone regime, which has a poor record on transparency, has pledged it will reveal the data recorders' contents if they are found.
It is hoped any data contained within will indicate what caused the plane to divert. A range of theories including hijacking, rogue pilot activity and aircraft malfunctions have been speculated.
The New Straits Times quoted a source with "intimate knowledge" of the deal saying it also specified where any passenger remains would be brought and who would carry out autopsies.
A survey by Malaysia's leading independent polling firm released earlier this week found that only 26 percent of Malaysians believed the government was being transparent about MH370.
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