available data, the aircraft flew south until it ran out of fuel and crashed into the sea, according to a source familiar with data the U.S. government is receiving from the investigation.
In the south, any debris from MH370 would have been widely dispersed by Indian Ocean currents in the week since it disappeared.
SCATTERING OF ISLANDS
The southern Indian Ocean, between Indonesia and Australia, is broken up only by the Australian territories of Christmas Island, home to asylum seeker detention facilities, and the Cocos (Keeling) Islands some 2,000 km (1,240 miles) northwest of Perth. The Cocos Islands have a small airport to serve the islands' combined population of just 3,000 people.
Further south, the only habitation is the handful of research stations on the scattering of tiny French-run islands including Kerguelen - a group of volcanic outcrops between Africa, Australia and Antarctica. While home to several powerful astronomical scanners and radar, there is no airport and it is seen extremely unlikely the aircraft could have made it that far.
The shipping route from Western Australia north to Asia and Europe is considered relatively quiet in global shipping terms, despite the large amount of iron ore and other resources that are shipped from Australia's northwest ports.
Ships track north staying close in to the West Australian coastline and then head north through Indonesian waters into the South China Sea or northwest toward the Red Sea.
Australia's civil aviation radar extends a maximum of just 200 nautical miles (410 km) off the coast, the civil aviation authority source said, and was used only for monitoring scheduled aircraft on approach into the country and subsequent landings.
There are just two primary radars on the west Australian coast, one in Perth and one further north in Paraburdoo, which has even less range and is used to monitor mining traffic heading to the nearby Pilbara region.
Australia's Civil Aviation Authority relies on aircraft ADSB (automatic dependent surveillance broadcast) to ping information to commercial satellites, such as telecoms firm Optus' four telecommunications satellites, and back to ground control.
The source said that this was the case with flights by Emirates Airlines, which all fly over the Indian Ocean to Australia, but it did not provide a specific radar plot.
Australia does not have any government satellites.
The Australian military has an over-the-horizon radar network that allows it to observe all air and sea activity north of Australia for up to 3,000 km (1,860 miles). This encompasses all