British Airways cabin crew have moved into day two of their strike in protest against job cuts and changes to work practices.
Members of Britain's biggest trade union, Unite, walked out on Friday night after talks between union joint leader Tony Woodley and BA chief executive Willie Walsh broke down.
Unite says the airline does not want to negotiate, while BA says the industrial action is deeply regrettable.
BA says it is the biggest contingency plan has ever launched and has leased planes from other airlines to keep two-thirds of its passengers in the air, the ABC reports.
The airline it has got off to a good start at Heathrow and Gatwick airports, but the union claims that some planes are beginning to stack up on the ground as a result of the strike.
Prime Minister Gordon Brown has condemned the BA strike, saying it is in no-one's interest.
The airline is cancelling 1100 flights out of the 1950 scheduled to operate during the strike, the BBC reports, though it has said that 65% of passengers will reach their destination.
The union plans a second three-day walkout starting on 27 March.
British Airways suffered a loss before tax of Stg 342 million for the nine months to December 2009 and says it needs to cut costs in order to survive.
Separately, British railway signal workers have voted in favour of strikes in a dispute over jobs and safety, though they have not named a date for the action.