The good news is that they must also now offer at least some compensation if your flight is delayed by two hours or more. Insurers, on the other hand, rarely pay out until you have been delayed for at least 12 hours.

If your flight is delayed for two hours or more, for example, the airline must offer you meals and refreshments, the use of a phone and hotel accommodation if necessary. If the delay is for more than five hours, it must offer to refund your ticket.

However, there is no legal requirement for airlines to offer a refund if passengers decide to change their travel plans because of personal safety concerns or to avoid disruption — perhaps in the wake of a security alert.

Carriers are required to inform passengers of their rights when they book, but the information is usually buried in the terms and conditions.

Another common complaint involves airlines cancelling a flight and putting passengers on to a later flight from or to a different destination. In such circumstances, they are required to cover the cost of getting you to the original airport, but passengers are rarely told this.

AUC chief executive Simon Evans said: “There is a lack of clarity in the regulations, which has given airlines flexibility.

“Dealing with complaints is a very expensive cost that some airlines, particularly the no-frills operators, are keen to avoid.”

The AUC website (caa. co.uk/auc) has a page of advice for those who experience problems.

Its top tips include trying to speak to someone on the spot — they may be able to sort out the problem straight away — and making a note of any staff names, times and other relevant information.

If you are making a complaint after the event, the AUC advises writing to, rather than calling, the airline, tour operator or airport and making it clear that you require compensation.

Evans said: “Be as unemotional as you can. The best approach is to set out the facts and also to give the airline a clear indication of what sort of compensation you expect.”

If that fails, the next step is to elevate your complaint by writing to the chief executive.