Search planes scoured a remote patch of the Indian Ocean but came back empty-handed after a 10-hour mission looking for any sign of the missing Malaysia Airlines jet – another disappointing day in one of the world's biggest aviation mysteries.
Australian officials pledged to continue the search for two large objects spotted by a satellite earlier this week, which had raised hopes that the two-week hunt for the Boeing 777 that disappeared on March 8 with 239 people on board was nearing a breakthrough.
But Australia's acting prime minister, Warren Truss, damped down expectations.
"Something that was floating on the sea that long ago may no longer be floating – it may have slipped to the bottom," he said.
In Kuala Lumpur, where the plane took off for Beijing, the country's defence minister thanked more than two dozen countries involved in the search that is stretching from Kazakhstan in Central Asia to the southern Indian Ocean, and said the focus remained on finding the jet.
"This going to be a long haul," Hishammuddin Hussein said.
The search area indicated by the satellite images – some 2,500km (1,550 miles) south-west of Perth – is so remote it takes aircraft four hours to fly there and four hours back, leaving them with only enough fuel to search for about two hours.
Yesterday, five planes made the trip.
While search conditions had improved since Thursday, with much better visibility, the Australian Maritime Safety Authority said there were no sightings of plane debris.
Malaysian authorities have not ruled out any possible explanation for what happened to the jet, but have said the evidence so far suggests it was deliberately turned back across Malaysia to the Strait of Malacca, with its communications systems disabled.
They are unsure what happened next.