Few things are as likely to get a holiday off on the wrong foot as a flight delay. Under EU regulations, airlines are now required to provide meals and accommodation for passengers when there are significant delays in flights. They must also pay compensation when flights are cancelled, unless this is because of ‘extraordinary circumstances which could not be avoided even if all reasonable measures had been taken’.

One issue which has not been clearly addressed is when a delay becomes a cancellation. Recently, a dispute between Thomas Cook Airlines (TCA) and a disgruntled passenger provided guidance on the view that the courts might take.

It involved David Harbord, an economist who has taught at universities throughout the world, who was flying to Vancouver from Stansted Airport last year. The flight was cancelled and the passengers were told to board buses to Manchester, where the flight would commence the following day using the same flight number. Mr Harbord refused to travel and made an alternative booking. He then sued TCA for compensation.

TCA argued that no compensation was payable. In their view, the flight was delayed, not cancelled. Secondly, the switch was made necessary by an engine problem on an aircraft, which was an unforeseen fault which constituted extraordinary circumstances which could not be anticipated. The fault was, however, with a different aircraft, not the one on which Mr Harbord had been scheduled to travel. TCA had cancelled his flight in order to make best use of their fleet and minimise delays to their passengers as a whole.

The airline's arguments were rejected. The occurrence of a fault in a plane other than the one which was to be used for the flight could not trigger the 'get out' clause for cancellation. A flight that leaves from a different airport on a different day is not the same flight delayed, but a different flight, even if it bears the same flight number.