Q & A
I have heard horror stories of passengers with a confirmed reservation who have been bumped from overbooked flights when they arrive at the airport in good time. How likely is this to happen, and what can one do if it does? -- Jeremy Woolfe, Brussels
It's down to the law of averages catching up with you. Bumping, or 'involuntary denied boarding,' happens because airlines typically oversell flights by up to 50 percent to compensate for people who fail to turn up.
For instance, Judith Goldberg of Tel Aviv writes: 'I flew Austrian Airlines  from Tel Aviv to Delhi, via Vienna. When I arrived at the transfer desk, two and a half hours before the Delhi flight, I was told I had no seat reservation, the flight was overbooked, and I would be wait-listed -- no matter that I had paid months in advance and was joining a tour. Austrian did give me a hotel for the night and paid for a night at my hotel in Delhi.'
The United States Department of Transportation requires airlines to first ask for volunteers if a flight is overbooked. This may be conducted as a kind of auction at the gate, usually for cash or travel vouchers plus travel on another flight. If you are bumped involuntarily, airlines must pay you $200 if they can't get you to your destination within two hours of your original arrival time on domestic flights and four hours on international flights. If the delay is longer, you are entitled to up to $400 plus overnight expenses and a refund on your ticket.
The European Union has similar rules that apply to all passengers (whether or not they are residents of a European Union country) who have a confirmed reservation and who have checked in on time for a flight to or from any airport in the European Union (including French overseas territories) on an airline based in the union.
If a flight is overbooked, airlines must call for volunteers to give up their seats in exchange for a ticket refund and 'agreed benefits' including a free onward flight. If you are not a volunteer, you are entitled to 250 euros (about $328 at $1.31 to the euro) for a flight up to 1,500 kilometers (932 miles), 400 euros for a flight of up 3,500 kilometers (2,175 miles) and 600 euros for longer flights, along with a ticket refund and a free flight back to your starting point.
There's no sure-fire way to avoid being bumped. But it helps to reconfirm with the airline, get a preassigned seat (it's always a bad sign if you can't), turn up early at the airport, get your luggage aboard and be a member of the frequent-flier program, particularly at an 'elite' level.
ROGER COLLIS