Airline passengers should be allocated seats based on how much carry-on luggage they have, according to scientists who devised a formula for speedy boarding.
Lengthy queues at departure gates could be substantially cut by spreading passengers with several bags around the cabin and ensuring they sit in window seats wherever possible, they said.
Allied with other tricks such as asking passengers in window seats to board first and those in the aisle last, experts estimate carriers could passengers’ waiting time by more than 25 per cent.
The system currently used by most airlines of calling passengers at the back of the plane to board first is so inefficient that even allowing them to choose their own seats and board at random would be faster, they added.
Dr R. John Milne, of Clarkson University in New York, and Alexander R. Kelly, an independent researcher, explored the effect of passengers’ hand luggage on the time it took them to board a plane.
Previous studies have already established that a passenger with two items of hand luggage takes 60 per cent longer to board a plane than one with no bags, while average boarding speeds slowed from 20 passengers per minute in the 1960s to nine per minute in 1998 as use of hand luggage increased due to fees for checking bags.
Dr Milne said assigning passengers with the most bags to window seats, preferably spread out from the front to the back of the plane, and allowing them to board first would help solve the problem.
Passengers with just one bag should then be assigned to middle seats and board second, while those with none occupy the aisles and come last.
“Let’s say I come onto the plane and have an aisle seat and have two bags with me – by the time I get onto the plane those [overhead] bins get pretty full and it’s harder to find a spot,” he explained.
“If I am with the first passengers to board, I am more likely to find a spot for two bags.”
The theory builds on previous work by the physicist Jason Steffen, who showed that asking passengers in window seats to board first could reduce queues by 24 per cent.
The fastest possible method, set out by Dr Milne in the Journal of Air Transport Management, would be for passengers with the most luggage to be given seats by windows and spread as far apart as possible, before boarding in a carefully choreographed order.
Window seat passengers in odd numbered seats on one side of the plane would board first, followed by those in even numbered seats, or vice versa. The process would be repeated for window seats on the other side of the cabin, then for middle seats and aisle seats in the same manner.
“If you have a row to separate these people they aren’t really bumping into each other, that’s the idea,” Dr Milne said. “They can all be storing their luggage at the same time.
“The Steffen method by itself cuts the time by a lot…with the luggage [distribution] it is more like an extra two to three per cent beyond what you get doing Steffen alone.”
The formula would be unlikely to work in practice because of the need for families to board at the same time and sit together, for example, but elements could be used to significantly reduce waiting times, he suggested.
Airlines could allow priority passengers or those who pay extra to choose a seat while distributing the remainder around the cabin as efficiently as possible, he said.
United Airlines already asks passengers in window seats to board first and those along the aisle last, except premium customers who board first, and families who can continue to board together.
Customers could be assigned a queue number by stating how many carry-on bags they expect to bring with them when they check in online, or even by software which could estimate how many bags they are likely to have, Dr Milne claimed.
A passenger whose return flight is booked the same day as their outward journey is likely to have less carry-on luggage than one who is returning several days later but has not checked a bag, for example.
“Say you have six business travellers who have not checked any bags who are all leaving on Monday morning and coming back on Friday night, and you stick them all in the same row, you are asking for congestion,” he said.
“So you can make estimates of how much luggage people are likely to be bringing on board and that way you don’ t have to ask people anything or check their bags.”