Looking to save money and time, the airline industry has for years tried to come up with the fastest way to seat passengers.
Some airlines board from the back of the plane to the front. Others seat passengers in the window seats first, then the middle seats and finally the aisle seats.
Now an academic study suggests airlines could cut boarding time by seating passengers based on how many carry-on bags they are hauling.
The study from Clarkson University School of Business in New York recognises that a lot of boarding time is wasted as passengers shuffle around the cabin looking for space to stow their carry-on bags in the overhead compartment.
Under a boarding method suggested by R. John Milne, an assistant professor of engineering management, passengers are seated from the back of the plane to the front and from the windows to the aisles.
Milne adds another wrinkle: He also suggests airlines seat passengers in a way that spreads the carry-on luggage throughout the plane. In each row, the airline would seat at least one passenger with two bags, one passenger with one bag and one passenger with no bags.
"So now you don't have delays where people are trying to cram all their luggage in the overhead compartment," Milne said in an interview.
Milne's study found that this boarding method can cut seating time by an average of 3 per cent compared with a back-to-front boarding scheme. For a large carrier such as Delta Air Lines, the process could save as much as US$10 million a year, according to his study, published this month in the Journal of Air Transport Management.
So far, the boarding process has been tested only on a computer simulator, and Milne said he hasn't offered the idea to any airline.