But they lost one in London, reports CBS News Correspondent Steve Holt.
An Australian judge Friday gave a group of DVT plaintiffs the right to sue airlines for damages, while a London judge, also on Friday, decided plaintiffs cannot try to make the airlines pay.
A group of 55 DVT survivors and relatives of victims who died from the condition were seeking compensation from 27 airlines for an alleged violation of duty of care.
Brenda Wilson lost her son Neil, after he flew to Spain.
"He died from a massive heart attack. The clot went straight to his heart and killed him instantly," she said.
The London plaintiffs are expected to appeal. Millions of dollars in potential damages are at stake.
The judge made his ruling on the preliminary issue of whether DVT can be considered an accident under terms of the 1929 Warsaw Convention and therefore whether the airline was liable for a resulting injury or death.
David Learmount, editor of Flight International magazine, claimed that there was no direct link between DVT and air travel, specifically.
"It simply has not been established that there is any form of direct link between DVT and airline travel, specifically," said Learmount.
He also alleged that airlines were often obliged to allow people on board flights that they considered unfit to travel.
"They (the airlines) are very often confronted with passengers who shouldn't really be traveling, their health isn't good enough," he said. "If the passenger insists then the airline can't stop them boarding and they also can't stop them suing afterwards."
DVT is a condition that causes sufferers to develop potentially fatal blood clots during long-haul flights.
One British victim, Emma Christoffersen, died of a blood clot after sitting for 20 hours on a flight from Australia to Britain in October 2000.
Her parents, Ruth and John Christoffersen, set up Victims of Air Related Deep Vein Thrombosis Association to raise awareness of the condition and ways to minimize risks.
"We realized that Emma wasn't the only one," said Ruth Christoffersen. "Emma wasn't the first and tragically she's not been the last. There have been many since."