United Airlines will start boarding passengers in economy class with window seats first starting next week, a move designed to reduce the time planes spend sitting on the ground.

The airline said in an internal memo that it will implement the plan on Oct. 26. The plan 鈥� called WILMA, for window, middle and aisle 鈥� was tested at several locations and deemed to shave up to two minutes off boarding time.

Variations of the WILMA approach have existed for many years.

鈥淚t spreads people out along the aisle of the airplane so that more people can put their luggage away at the same time. That鈥檚 the main thing that speeds up the boarding process,鈥� says Jason Steffen, an associate professor of physics at the University of Nevada, Las Vegas, who a decade ago.

The change will begin with passengers in the fourth boarding group. Customers in first class and business class will see no change in their routine, and there鈥檚 also no change for those with priority-boarding privileges, including travelers with disabilities, unaccompanied minors, active-duty military, and families with children who are 2 or under.

United said that when multiple customers are on the same economy reservation, such as families, they will be allowed to board together.

The new policy will be used on domestic flights and some international flights.

Airlines have long searched for the perfect boarding process. Orville and Wilbur Wright to see who got the lone seat on their flying machine.

United is making changes now because, it says, average boarding time has increased by two minutes since 2019.

Tinkering with the boarding process has increased since airlines began charging fees for checked bags more than a decade ago. Those fees encourage passengers to bring carry-on bags, which generally are still free except at low-cost carriers such as Spirit and Frontier.

鈥淎ny time you have to wrestle with luggage up over your head, it鈥檚 going to slow things down,鈥� Steffen said.

Two minutes doesn鈥檛 make much difference on a transatlantic flight, but on heavily trafficked shorter routes 鈥� think about the Northeast, or between the Hawaiian islands 鈥� delays tend to cascade, pushing late-day flights farther and farther behind schedule.

If a few passengers dawdle while stowing their bag and finding their seat, it can make the difference between a flight being on time or late in the government鈥檚 official statistics.

The last passengers to board face the risk that there won鈥檛 be room for their carry-on bag in the overhead bins. That leads passengers in late boarding groups to crowd the gate area so they can jump in line ahead of others. Gate agents and seasoned travelers call the line jumpers 鈥済ate lice.鈥�

READ ALSO: