As many as 50,000 passengers a year are being bumped off flights in the UK as airlines overbook to maximise profits.
Experts said “denied boarding” is becoming increasingly common because of competition among airlines, which has led carriers to sell too many tickets to avoid flying with empty seats.
The disclosure came as video footage emerged of a passenger being dragged off a United Airlines US domestic flight by security officers.
Film taken by other passengers showed the man being pulled off the flight at O’Hare international airport in Chicago on Sunday.
The man – who claimed to be a doctor – had been picked at random to leave the Louisville-bound flight after the airline unsuccessfully appealed for volunteers to give up their seats, according to reports.
Passengers had been offered $800, a hotel room and a flight the next day to allow other United airline staff to travel.
Airlines traditionally sell too many seats in the expectation that some passengers – usually business travellers who book multiple tickets – will fail to show up or cancel at the last minute.
Less than 0.02% of passengers flying in or out of the UK were denied boarding in 2015, according to the Civil Aviation Authority. This is equivalent to a maximum of 50,330 travellers.
The figures covered airlines overbooking flights and bringing in a smaller-than-planned aircraft at the last moment.
A report by the CAA said that all airlines operating the policy “call for volunteers first and tried to do so as early as possible, sometimes being able to reach passengers before they had set off for the airport”.
Under EU rules, airlines must seek volunteers to give up their seats before forcing passengers to move to another flight.
Passengers being bumped off are entitled to up to €600 (£512) compensation, depending on the flight’s length and the time spent waiting for a replacement.
Aviation consultant Chris Tarry told The Times that airlines were “well versed” at overbooking, with passengers rarely being forced off.
It was usually employed by premium carriers such as British Airways with a large number of first and business-class travellers, he said.
However, he added: “It is reasonable to say that this is something that low-cost carriers will do, or are considering doing, more of simply because things are getting more competitive. It is still quite a marginal business and carriers are looking at every way they can to make a profit.”
Figures suggest that overbooking is more prevalent in the US. According to the Bureau of Transportation Statistics, 552,000 passengers were denied boarding by the biggest carriers in 2015, equivalent to 0.09% of the total.
This included 46,000 passengers subjected to “involuntary” bumping off.
In the United Airlines incident, passengers were initially offered $400 and a hotel stay to make way for airline staff. The offer was then doubled but still no one volunteered, leading the airline to pick four people at random.
According to other passengers, a couple left the flight peacefully but the man at the centre of the dispute refused, saying that he was a doctor and needed to be in Louisville the next morning.
Three security staff boarded and dragged him away before he broke free and ran back on board with a bleeding face. Other passengers were then taken off as medical staff attended. The flight eventually took off two hours late.
The Chicago Department of Aviation said last night that one security officer had been suspended.
United CEO Oscar Munoz said: “This is an upsetting event to all of us here at United.
“I apologise for having to re-accommodate these customers.
“Our team is working with a sense of urgency to work with the authorities and conduct our own detailed review of what happened.
“We are also reaching out to this passenger to talk directly to him and further address and resolve this situation.”