Australian jet joined a race against time Friday to reach solo sailor Abby Sunderland after the US teenager triggered emergency beacons after battling 6-metre swells and 90-kilometre-per- hour winds in the middle of the Indian Ocean, DPA reported.
Maritime Safety Authority (AMSA) spokeswoman Carly Lusk said a chartered Airbus had taken off from Perth and was on a four- hour flight heading for the search area 3,600 kilometres from the Western Australia state capital.
"Going by the actual drift of the beacon in the water we are hoping that she is still inside the vessel," Lusk told public broadcaster ABC.
She said crew on the Airbus would try to spot Sunderland's sailboat, Wild Eyes, and contact the girl by VHF radio when they reached the search area.
According to Lusk, the nearest ship is 500 kilometres away and was not expected to get to the rescue zone for 24 hours.
Sunderland began her round-the-world voyage in January, hoping to trump Australian Jessica Watson's mark and become the youngest circumnavigator.
Watson, who was five months older than Sunderland when she set off from Sydney, completed the trip last month, days short of her 17th birthday.
Technical problems aboard Wild Eyes forced Sunderland into port in South Africa, ending her bid to beat the solo-and-unassisted record.
Laurence Sunderland told the ABC that he had grave fears for his daughter, saying his hope was that the keel had broken off and Abby was in a "bubble" inside Wild Eyes.
"Right now we're hoping that if indeed the boat is upside down, then the keel is actually off the boat and giving the boat a positive flotation factor, and that she's inside the bubble, safe," he said in a telephone interview from his home in California.
"However, we all have breaking points, and she's had a couple of boisterous days out there, so it's going to be a bit of a miracle here," he said.
On a blog in which Abby documented her trip - http://soloround.blogspot.com/ - her parents posted a message Thursday about her current plight.
They said that Abby had manually activated both the boat's emergency beacon and a second beacon carried on her person. But the vessel's water-activated beacon had not gone off, "so we are hopeful that the boat is still upright."
"Abby has all of the equipment on board to survive a crisis situation like this," they wrote. "She has a dry suit, survival suit, life raft, and ditch bag with emergency supplies. If she can keep warm and hang on, help will be there as soon as possible."
Wild Eyes was "designed for travel in the Southern Ocean and is equipped with 5 airtight bulkheads to keep her buoyant in the event of major hull damage ... and is designed to self-right in the event of capsize," the blog said.
Abby's last post of her own, dated Wednesday, said: "The last few days have pretty busy out here. I've been in some rough weather for awhile with winds steady at 40-45 knots with higher gusts."
Watson family spokesman Andrew Fraser said a message of hope had been sent to Sunderland's family. "We're hoping she is OK and are trying to stay positive," Fraser said.