Checking in at the US Airways counter in Phoenix for a flight to Cabo San Lucas, Mexico. There were enough no-shows that no one was bumped.
PHOENIX — The summer travel season is under way, and so many planes are expected to be full that, if you are bumped, you could end up waiting days for a seat on another flight to the same destination.
The number of fliers bumped against their will is expected to reach a high for the decade this year.
True, those travelers — about 56,000 of them — still represent only a small fraction of all passengers. But the increasing difficulty of rebooking bumped passengers has made the experience more maddening for fliers, and for the airline workers who deliver the bad news.
Overbooking is one of many airline practices that are complicated by crowded planes. Airlines are running closer to capacity than at any point during the jet age — an expected 85 percent or so full this summer, which means all the seats on popular routes will be taken.
Airlines, of course, overbook to avoid losing billions of dollars because of empty seats. Inevitably, though, they guess wrong on some flights and too many people arrive at the gate.
Vouchers for free flights have long been used to convince enough passengers to stand aside and wait for the next flight. But now, more people are refusing the voucher — which can vary from a small dollar amount to a round-trip ticket anywhere an airline flies (people who are involuntarily bumped get up to $400 for their troubles).
The reason is that fliers have figured out that with flights full, there are fewer and fewer seats to be bumped to.
The number of people bumped involuntarily — those refusing the voucher — rose 23 percent last year and kept rising in the first quarter of this year.
The ranks of all bumped passengers last year, 676,408, was small — unless you were one of them — compared with the 555 million total airline passengers.
Airline workers, of course, do not like bumping, either.
"It's embarrassing," said Brigid Mullin, a gate agent for US Airways here. On one or two flights a day, Ms. Mullin is left to explain to passengers that US Airways sold more tickets than it has seats on the plane.
"People are going to yell," Ms. Mullin said.
Mr. Beall, the US Airways official, said, "Employees call in sick because they don't want to deal with overbookings."
At an employee meeting just after the merger, Mr. Parker was confronted about the issue by John Martino, then a gate agent in Boston. "You know you're going to be yelled and screamed at to the point you have to call the police," he said.
Mr. Parker replied: "Why do we do so much of it? We will overbook as long as we allow people to no-show for flights; 7 to 8 percent of our customers are no-shows."
At some airlines, the no-show rate is higher, as passengers take advantage of refundable tickets, which include those bought by business travelers at the last minute.
The potential impact is huge. US Airways had revenue of $11.56 billion last year and would have lost out on $1 billion or more of that had it not overbooked, the company said.
And with profit of just $304 million for the year, and with other airlines operating on similarly slim margins, "we'd probably all go bankrupt" without overbooking, Mr. Trenga said.
That said, Mr. Trenga acknowledged, "People view overbooking as something not on the up-and-up."
So, while he tells his neighbors that he oversees pricing at US Airways, "I conveniently forget to mention the overbooking part." US Airways rates in the middle of the industry pack on bumping passengers.
Of course, airlines could end no-shows and the need for overbooking by selling only nonrefundable tickets. JetBlue Airways does that, and no-shows lose the value of their ticket.
But business travelers, who pay the most, want refundable tickets and even JetBlue is considering offering them.
The revenue lost by leaving a seat empty — a spoiled seat, in industry parlance — typically exceeds the cost of compensating a bumped passenger. Only fear of angering people keeps airlines from overbooking more.
No-show rates used to be much higher — 20 percent or more for many airlines. Many travel agent reservations were unreliable. Other bookings were duplicates.
At US Airways, into the late 1990s, the no-show rate was about 14 percent, Mr. Beall said, and its ability to overbook accurately suffered. "We were stuck in an overbooking quagmire," he said. "We had scant credibility" with gate agents.
But even after cleaning up its reservations and reducing no-shows to 7 percent to 8 percent, no-shows still vary widely among flights.