Heathrow's chief executive Colin Matthews has said the severe snow disruption at Heathrow could happen again due to the packed schedule at the airport.
Hundreds of passengers were forced to spend the night at Heathrow over the weekend after 37% of flights were cut following heavy snow in London.
Bristol airport is still suffering severe disruption and Heathrow is still experiencing delays despite the snow thawing in many areas.
There is a weather warning for snow in eastern Scotland, an ice warning across much of the UK and weather reports suggesting on Friday there could be another spell of snow, especially to higher ground in northern Britain.
In an interview with the Telegraph, Colin Matthews said because Heathrow acts at capacity every day, flights cannot be rescheduled to arrive or leave later in the day if they are delayed due to the snow.
He said: "I would like to promise that it will never happen again. But I can't do that because it would be dishonest."
"While other airports can move flights to gaps later in the schedule, Heathrow cannot. It is full all day, every day - which is exactly why we have argued for the need for more capacity at London's hub airport.
"No matter how many snow ploughs an airport buys, no matter how many people it has on shift, no matter how good its planning, there are some physical limitations we have to accept. That is not to make excuses. It is simply a statement of fact."
Wednesday, January 23, 2013