DALLAS — Getting people on and off an airplane quickly is so complicated that even an astrophysicist couldn't figure it out.
Jason Steffen, a research fellow at Northwestern University, normally contemplates things such as axion-like particles. But after waiting in one boarding line too many, he turned to the mysteries of airline seating.
"I thought there had to be a better way," he says.
So, after a series of calculations, he deduced that the best system would be a combination of filling all the window seats first, then all the middle ones and then the aisle ones, while also having the passengers board every other row.
There was just one problem — passengers would have to board in precise order. Good luck with that. These are the same passengers who don't turn off their phones even after they're told it's a federal law.
"Well," Steffen observes, "I understand why airline people aren't calling me."
But the search for the perfect boarding process goes on.
Most airlines allow first-class and other elite customers to board first. After that, some fill the rear rows first and work toward the front.
Others fill window seats and work in toward the aisle. Some used to employ a hybrid called the reverse-pyramid. Southwest Airlines has random seating: There are no assigned seats — passengers sort things out themselves. They can pay extra to be near the front of the boarding line.
All of this matters more than you might think.
Passengers want to board early to find space in the overhead bins for their rolling carry-on bags. For airlines, every minute that a plane sits at the gate makes it more likely that the flight will be late, hurting the carrier's on-time rating and causing passengers to miss connecting flights.
There's an economic cost to running late, too. Researchers from Northern Illinois University say that at one major airline, which they didn't identify, every extra minute at the gate added $30 in costs.
American Airlines, which uses a back-to-front system for boarding coach passengers after it takes care of elite customers, says that it takes about 25 minutes to board passengers on a smaller, narrow-body plane such as a Boeing 737 and about 35 minutes on a bigger plane such as a Boeing 777.
In recent weeks, United and American — the nation's biggest and third-biggest carriers — have rolled out new strategies for faster boarding.
— American is letting passengers board sooner if they don't put anything in the overhead bins. The idea is to get more people seated quickly before passengers with rolling bags clog the aisle.
— United reduced the number of boarding groups from seven to five while adding lanes in gate areas — from two to five at big airports. That's designed to eliminate "gate lice" — the name road warriors use for those anxious passengers with big carry-ons who cause a traffic jam by creeping forward long before their group is called.
American and United tested their new procedures in a handful of airports before rolling them out across the country in time for the peak summer travel season. United CEO Jeff Smisek says his airline's new method has helped cut departure delays related to boarding by more than 60 percent.
Boarding methods go back to the dawn of commercial flight, but they've gotten more complicated as the airlines have created different classes of passengers and sold the right to board early.