By the time coach travelers are called, the overhead bins seem to be already full.
Airlines have been boarding passengers since the first commercial flight, but as they have added new classes of seating to their cabins and new fees for priority boarding — all in the name of more revenue — they have slowed down the whole process.
Checked-baggage fees have only added to the problem, because travelers now take more roll-ons onboard, blocking the aisles as they try to cram their belongings into any available space.
And that’s not to mention the fact that planes are now fuller.
That is why some airlines have gone back to the drawing board to rein in a lengthening process. As it is, boarding time has doubled over the last decades, according to research by Boeing. It now takes 30 to 40 minutes to board about 140 passengers on a domestic flight, up from around 15 minutes in the 1970s.
“They should have a different line for people with carry-ons like they do at baseball games with bags,” said Brian Proffit, who was flying to Houston from New York with Delta Air Lines. “The boarding process has become worse than the security lanes.”
One airline did figure out a way to sharply cut boarding time. Spirit Airlines found that passengers got to their seats much more rapidly once it started charging $20 to $40 per carry-on bag. Since it’s $2 cheaper to check a bag, more passengers do, and Spirit claims its “stress-free boarding” saves six minutes on average.
Others are reluctant to take such a drastic step for fear of alienating customers.
It should be no surprise that boarding has become one more frustrating step in airline travel. Or, as Mark E. DuPont, the vice president for airport services planning at American Airlines, put it: “Boarding can be like driving behind a slow-moving truck that you can’t overtake.”
Airlines have tried all kinds of elaborate tricks over the years to leave the gate on time. Some board passengers in the back rows first, while others give priority to those with window seats, and some come up with elaborate combinations, including one no longer used, known as the “reverse pyramid.”
But passengers can be unpredictable.
“The real world has wrecked their optimization plans,” said Matthew Daimler, the founder of SeatGuru, a Web site that helps passengers find the best seats on a particular plane.
American Airlines changed the way it boarded its planes in May. It still gives priority to business passengers and frequent fliers but then boards passengers who paid an extra $9 to $19 to get on early, guaranteeing they will find space to stow their bags.
The rest of the passengers are then brought in as three groups, sorted in an attempt to spread them out more evenly through the cabin and allow more people to find their seats faster. The approach also helps passengers stow their luggage more efficiently, nearer to their seats, allowing more people to find overhead space and cutting the number of bags that need to be checked at the last minute — a common cause of delayed flights.
The new method has cut boarding by four to five minutes, Mr. DuPont said.
All the extra fees have been a major benefit to the airlines’ bottom lines. According to estimates by Amadeus, a global distribution service, they will add up to $12.5 billion in 2011 for major United States airlines, up 87 percent from last year.
The challenge of boarding is thornier for narrow-body planes with single aisles that are used on domestic flights than on the larger planes on international flights where passengers have two possible pathways.
A scientist once said the problem of boarding a single-aisle plane was a real-life application of Einstein’s theory of relativity, where passengers are constrained in their movements through space and time.
A few years ago, Jason H. Steffen, an astrophysicist at Fermilab in Chicago, figured there had to be a better way to board after he was held up on the jetway while waiting for a flight to Washington. “If the process was efficient, there would be no line,” he said.
He set out to solve the problem using a “Markov chain Monte Carlo optimization algorithm” — a mathematical program well suited to the kind of haphazard events that occur in an airplane cabin. Much to his surprise, he found that the common back-to-front method was among the slowest: passengers must wait for those ahead of them to stow their bags and sit down. It is far better, it turns out, to let passengers board randomly. Mr. Steffen claims he found the fastest way, which involves boarding passengers from the back who are seated two rows apart.
“The lesson I learned comes down to this: you want to spread passengers out and not concentrate them while boarding,” he said. But the method is unlikely to be picked up because the airlines say it is too complicated.
Others have also searched for the holy grail of boarding. In 2002, America West Airlines, which later merged with US Airways, hired industrial engineers from Arizona State University to speed up the boarding process. The group came up with an approach that they called the “reverse pyramid.” It begins with passengers assigned to window seats in the back, and gradually makes its way to the front of the plane in a staggered pattern.
That saved time, but US Airways dropped it in 2007 because some passengers without elite status sitting in the front could not find space for their bags.
“Overhead space has really become a premium product,” said Kerry Hester, the senior vice president for operations planning at US Airways.
Another approach is used by Southwest, which says it can board its planes in around 15 minutes. It says the root of the delays is the practice of assigning seat numbers. Southwest’s passengers are instead assigned to one of three boarding groups, and then given a number based on the time they checked in.
Passengers who buy a premium “Business Select” ticket are guaranteed to board ahead of everyone, followed by Southwest frequent fliers and passengers who bought a $10 one-way “early-bird check-in” pass.
The airlines, meanwhile, keeps looking for what Scott O’Leary, managing director of customer experience at United, described as “the sweet spot between speed and a sense of order.”