Air travel has become one of the main forms of transport, whether it's short haul within Britain, or longer haul to Europe or other continents. In 2005 alone, 225 million people in the U.K. took flights. We take it for granted that most of the time we'll get on a plane pretty much when we're supposed to, and arrive more or less on time. But there's a great deal that can go wrong. Flights are delayed or cancelled, accidents might make you miss your plane, or your luggage might go astray. What rights do you have?

When You Buy Your Ticket

Before booking, you should know just how much you're paying. Does the quoted price include taxes? If you're paying by credit card, is there a surcharge, and if so, how much - it can add 1-2% to the total. Also, be aware of your ticket's restrictions. Quite commonly, these are no changes to your itinerary, no refunds, and you can't let someone else use your ticket. Also, you'll probably have to pay in full if you cancel. Any reputable travel agent can advise you about all the restrictions and ticket prices, whilst online retailers should make everything clear (including those terms and conditions) before your purchase.

If you book on a charter flight, you're committed to that flight. If you decide not to go, there's no refund or transferring the ticket to someone else.

Limited Mobility

If you have limited mobility, then wherever possible most airlines will accommodate your needs through their voluntary code of practice, and won't charge you for articles like wheelchairs. On the ground, the 1995 Disability Discrimination Act requires a "right of access," which means that all that airport facilities should be easily accessible to everyone.

If You Need To Change Your Flight

If you pay an extra fee, many airlines will allow you to change your flight (if they have available seats). However, be aware that others won't allow any changes to the booked itinerary.

If You Miss Your Flight

If long check-in queues make you miss your flight, most carriers will allow you to change to another flight. However, they're not obliged to do this, or even to pay you compensation. Still, in some instances you could be entitled to a "credit note" as compensation for a missed flight due to unforeseen circumstances.

Overbooking

If you're bumped from an overbooked flight within the EU and you confirmed your reservation and checked in on time, then you have a choice of cash compensation and an alternative flight or a full refund (the compensation is €250 up to 1500 km, €400 for EU flights up to 3000 km, and €600 for other flights). This only applies to regularly scheduled flights. Outside the EU, you must be offered an alternative flight.

Delays and Cancellations

Delays happen regularly. During 2005 over 30% of scheduled flights left more than 15 minutes late. If you're a victim (for these purposes, delays mean over two hours for 1500km or less, three hours for up to 3000 km and four hours for all other flights), the airline must provide you with free meals and refreshments and two free calls, e-mails or faxes. If the delay lasts overnight, then they must give you free hotel accommodation, transport between the hotel and the airport, and meals and refreshments. If the airline can't book you an acceptable alternative flight, then you have the right to a refund. If your flight's cancelled, the airline has to offer you other travel arrangements or a refund (you should also receive two free phone calls, faxes or e-mails). If they can't find you a flight that day, then they have to pay compensation, plus pay for your hotel accommodation, meals and refreshments, and ground transportation.

If they took all reasonable measures to avoid the problem or it was out of their hands (because of, say, security alerts or weather conditions), then the airline can't be held responsible for the cancellation.

Lost and Damaged Luggage

If your luggage is lost or damaged, report it before you leave the baggage claim area. The first thing to do is fill out the Passenger Irregularity Report (PIR). Keep a copy - you'll need both that and your luggage receipt if you're going to claim compensation. You have to make your lost luggage claim within seven days, and in writing (if you're on the outward leg of your journey, most airlines will give you money to purchase essential items). If your luggage is damaged, once again you should fill out a PIR and make your written complaint within seven days. Baggage delay liability is limited to £820.

The airline's liability regarding the loss, delay or damage of luggage goes by baggage weight, rather than value. Because of this, you should be wary of packing valuable or important items. If you're travelling with those, always use suitable containers and take out adequate travel insurance before you go.

Lost Ticket

Replacing a lost ticket isn't as simple as you think. You can be asked to pay for a new one, or the airline might say they'll refund your money only after the lost ticket has expired without being used - and that can take up to a year. Some will replace the ticket free of charge, but make you sign a form stating you'll pay for the ticket if someone else uses it.

Complaints

If you have a problem, try to speak to someone on the spot, and see if they can sort it out. If not, find someone in authority. Make a note of all the relevant information and get the names and addresses of other passengers who were witnesses. When you write to complain, tell the airline exactly what you want to be done about your complaint. If you expect compensation, tell them how much.

If all else fails, you can contact the Air Transport Users Council (020 7240 6061). The problem is that their decision isn't binding on the airline.