Snow and freezing temperatures continued to ground flights to and from Britain on Tuesday, with travellers hoping to get away for Christmas likely to suffer delays and cancellations for several more days.
British Airways said it expects to make a "significant number of cancellations" to its shorthaul services from London's Heathrow airport, which will again operate with just one of its two runways on Tuesday.
"Severe weather continues to cause significant disruption to our operation and will do so in the run up to Christmas," the airline said in a statement on Tuesday.
"Currently Heathrow has only one of its two runways operational and many areas of the airfield remain unusable, including areas around parked aircraft."
Ferrovial-owned BAA, which operates Heathrow, said the airport's south runway would remain closed on Tuesday, as on Monday, meaning the airport would be operating at significantly reduced capacity.
Thousands of passengers have been stranded at Heathrow, the world's busiest international airport, for days as flights have been delayed and cancelled.
Arctic conditions have caused major disruption to operations since Saturday, with BA expecting the travel chaos to continue. The Met Office has issued severe weather warnings for most of the UK for the remainder of the week.
BAA said 27 flights had arrived at Heathrow and 10 had departed by 0745 GMT on Tuesday -- more than at the same point on Monday.
"BAA has confirmed a limited schedule of flights to and from the airport, at least until 06.00 on Wednesday 22 December," BA said. "We have adjusted our schedule to fit with the capacity of the airport for both flight departures and arrivals."
The British government on Monday said it had relaxed regulations on night flights at Heathrow, allowing for arrivals until 0100 GMT each day until Christmas.
The harsh winter weather has grounded flights across northern Europe for days.
Eurocontrol, the umbrella group for air-traffic control across 38 countries, said more than 22,000 flights across Europe were cancelled on Monday but that more services would likely operate on Tuesday.
London's Gatwick Airport re-opened at 0600 GMT after closing overnight.
"We expect to operate the vast majority of our flights into and out of London Gatwick and London City, although some flights may be subject to delays," BA added.
Analysts believe the freezing conditions are hitting BA's profit by around 10 million pounds ($15.55 million) a day.
Shares in BA were 1% up at 268 pence by 0830 GMT, in line with the FTSE100 bluechip index, up 0.75%.