A new phase in the search for MH370 is set to begin, five months after the Malaysia Airlines flight disappeared without a trace. The next phase of the search, led by Australian authorities, will see underwater vehicles slowly scan 60,000 square km of the sea floor – an area approximately the size of Tasmania –  in the southern Indian Ocean, off the west coast of Australia. 'We are cautiously optimistic we will locate the missing aircraft in the search zone,' Deputy Prime Minister Warren Truss said today. Scroll down for video . The search will concentrate on a 60,000 sq km section off the west coast, roughly the size of Tasmania . There has been no sign of the missing Malaysia Airlines plane, which was flying from Kuala Lumpur to Beijing with 239 people on board, since it lost contact with air traffic control on March 8, 2014 as it was transitioning between Malaysian and Vietnamese airspace. The new phase of the search will commence in September and will involved underwater vehicles, towed by manned surface vessels, searching the ocean floor using side-scan sonars. The sonar data will be sent to the vessels and interpreted by personnel on board and then reviewed by analysts on shore. Over the last few months the Australian Transport Safety Bureau (ATSB) has been conducting a bathymetric survey to map the sea floor in the search area. So far 32,000 sq km of the 60,000 sq km search zone, which is approximately 80km wide and 700km long, has been mapped. Martin Dolan, Chief Commissioner of the ATSB, said the bathymetric survey is a crucial step before commencing the underwater search, revealing underwater volcanoes, canyons and valleys, which could make debris difficult to spot. The new search phase will concentrate on the area in close proximity to the 7th arc, which reaches from latitude 20 degrees south to 39 degrees south. It is believed that at the time MH370 reached this arc, the aircraft exhausted its fuel supply and began descending, leading search teams to believe the aircraft is unlikely to be more than 38 km west or 55 km east of the arc. Deputy Prime Minister Warren Truss (left), along with Mr Martin Dolan, Chief Commissioner, Australian Transport Safety Bureau announced the new phase of the search for MH370 . The search will involved unmanned underwater vehicles with sonar capabilities that will send data to vessels for analysis . The underwater search will be concentrated in the area around the 7th arc, which is believed to be where the plane ran out of fuel and began its descent . The government has contracted Dutch company Fugro to conduct the search operation, which will cost up to $52 million. Two Fugro vessels will be engaged in the search - the Fugro Equator and the Fugro Discovery, which is currently en route to Australia from the UK. The Australian government has committed to spending $80-$90 million on the MH370 search operation. Mr Truss said the government saw the search as their responsibility to the international community, but added he would be in discussions with Malaysian officials and representatives of other governments about sharing the cost of the operation. Mr Truss added that it was not clear how long the operation would take. 'Obviously we hope to find it on the first day, but it could take a year,' he said. Mr Truss said the search for the wreckage of MH370 was 'on schedule' and had not been affected by downing of Malaysia Airlines flight MH17, from Amsterdam to Melbourne, which was believed to be shot down over Ukraine, killing all 298 passengers and crew on board on July 17. 'Obviously Malaysia Airlines and the Malaysian government have to deal with... two extraordinary circumstances, two unique situations to deal with,' he said. The search for the missing plane has been led by Australia and conducted out of RAAF Base Pearce in Perth. Pictured: Australian Prime Minister Tony Abbott (left) and Malaysian Prime Minister Najib Razak (centre) Australia's Prime Minister Tony Abbott (centre) poses with leaders of international military operations, based in Australia and searching for Malaysia Airlines flight MH370 in March 2014 . Initial analysis of radar data and satellite communication messages following the disappearance of MH370 indicated it most likely crashed in the southern Indian Ocean, 2,500km south-west of Perth. But despite an international search effort led by Australia and operated out of the Pearce Air Force base in Perth, no debris from the plane has been found. The first phase of the search for the missing plane was a surface search of probable impact areas, conducted by an international fleet of aircraft and ships, which concluded on April 28. An acoustic search, accompanied by a search of the ocean floor in the vicinity of the acoustic detentions was then conducted, also without success. The ocean floor search was completed on May 28.
A new phase in the search for MH370 will commence in September .
Underwater vehicles will search 60,000 sq km of sea floor off the WA coast .
The Malaysia Airlines plane, carrying 239 people, vanished without a trace on March 8 .
Search will cost $52 million and take up to 12 months .
Deputy PM Warren Truss says the search is 'on schedule' despite the downing of MH17 .
Truss says he is 'cautiously optimistic' about finding the plane .
A new phase in the search for MH370 is set to begin, five months after the Malaysia Airlines flight disappeared without a trace. The next phase of the search, led by Australian authorities, will see underwater vehicles slowly scan 60,000 square km of the sea floor – an area approximately the size of Tasmania –  in the southern Indian Ocean, off the west coast of Australia. 'We are cautiously optimistic we will locate the missing aircraft in the search zone,' Deputy Prime Minister Warren Truss said today. Scroll down for video . The search will concentrate on a 60,000 sq km section off the west coast, roughly the size of Tasmania . There has been no sign of the missing Malaysia Airlines plane, which was flying from Kuala Lumpur to Beijing with 239 people on board, since it lost contact with air traffic control on March 8, 2014 as it was transitioning between Malaysian and Vietnamese airspace. The new phase of the search will commence in September and will involved underwater vehicles, towed by manned surface vessels, searching the ocean floor using side-scan sonars. The sonar data will be sent to the vessels and interpreted by personnel on board and then reviewed by analysts on shore. Over the last few months the Australian Transport Safety Bureau (ATSB) has been conducting a bathymetric survey to map the sea floor in the search area. So far 32,000 sq km of the 60,000 sq km search zone, which is approximately 80km wide and 700km long, has been mapped. Martin Dolan, Chief Commissioner of the ATSB, said the bathymetric survey is a crucial step before commencing the underwater search, revealing underwater volcanoes, canyons and valleys, which could make debris difficult to spot. The new search phase will concentrate on the area in close proximity to the 7th arc, which reaches from latitude 20 degrees south to 39 degrees south. It is believed that at the time MH370 reached this arc, the aircraft exhausted its fuel supply and began descending, leading search teams to believe the aircraft is unlikely to be more than 38 km west or 55 km east of the arc. Deputy Prime Minister Warren Truss (left), along with Mr Martin Dolan, Chief Commissioner, Australian Transport Safety Bureau announced the new phase of the search for MH370 . The search will involved unmanned underwater vehicles with sonar capabilities that will send data to vessels for analysis . The underwater search will be concentrated in the area around the 7th arc, which is believed to be where the plane ran out of fuel and began its descent . The government has contracted Dutch company Fugro to conduct the search operation, which will cost up to $52 million. Two Fugro vessels will be engaged in the search - the Fugro Equator and the Fugro Discovery, which is currently en route to Australia from the UK. The Australian government has committed to spending $80-$90 million on the MH370 search operation. Mr Truss said the government saw the search as their responsibility to the international community, but added he would be in discussions with Malaysian officials and representatives of other governments about sharing the cost of the operation. Mr Truss added that it was not clear how long the operation would take. 'Obviously we hope to find it on the first day, but it could take a year,' he said. Mr Truss said the search for the wreckage of MH370 was 'on schedule' and had not been affected by downing of Malaysia Airlines flight MH17, from Amsterdam to Melbourne, which was believed to be shot down over Ukraine, killing all 298 passengers and crew on board on July 17. 'Obviously Malaysia Airlines and the Malaysian government have to deal with... two extraordinary circumstances, two unique situations to deal with,' he said. The search for the missing plane has been led by Australia and conducted out of RAAF Base Pearce in Perth. Pictured: Australian Prime Minister Tony Abbott (left) and Malaysian Prime Minister Najib Razak (centre) Australia's Prime Minister Tony Abbott (centre) poses with leaders of international military operations, based in Australia and searching for Malaysia Airlines flight MH370 in March 2014 . Initial analysis of radar data and satellite communication messages following the disappearance of MH370 indicated it most likely crashed in the southern Indian Ocean, 2,500km south-west of Perth. But despite an international search effort led by Australia and operated out of the Pearce Air Force base in Perth, no debris from the plane has been found. The first phase of the search for the missing plane was a surface search of probable impact areas, conducted by an international fleet of aircraft and ships, which concluded on April 28. An acoustic search, accompanied by a search of the ocean floor in the vicinity of the acoustic detentions was then conducted, also without success. The ocean floor search was completed on May 28.
A new phase in the search for MH370 is set to begin, five months after the Malaysia Airlines flight disappeared without a trace. The next scan 60,000 square km of the sea floor – an area Australia. 'We are cautiously optimistic we will Deputy Prime Minister Warren Truss said today. concentrate on a 60,000 sq km section off the contact with air traffic control on March 8, 2014 will commence in September and will involved which will cost up to $52 million. Two Fugro