Back-to-front boarding ‘associated with greater risk of Covid-19 on planes’

Boarding aeroplane passengers from back to front may “substantially” increase the risk of Covid-19 infection when compared to inviting travellers to get on the aircraft on a random basis, according to scientists.

US researchers have found that seating passengers starting from the back, then the middle, and then the front of the plane roughly doubles the infection exposure compared with random boarding – where travellers get on the plane in no particular order and there is no preference given to business-class passengers.

In their findings, published in the journal Royal Society Open Science, the experts said that banning the use of overhead bins to stow luggage, keeping the middle seat empty, boarding window seats before aisle seats, as well as using a random boarding process could reduce exposure to coronavirus by up to 90%.

The study authors said their previous work looking at the spread of Ebola virus in airplanes suggested “the clustering of passengers while waiting for others to stow their luggage and take their seats” was associated with a greater risk of infection transmission.

To find out if there was a similar increased risk of coronavirus on planes, the researchers simulated several boarding processes to assess their impact on social proximity during boarding.

The team wrote: “Our results show that while a back-to-front boarding does indeed reduce exposure of seated passengers to those who are walking past them toward their seats, it increases proximity between pairs of seated passengers and pairs of passengers in the aisle.”

They added that the back-to-front boarding process “also increases exposure by approximately 50%” when compared with the traditional boarding methods used by US airlines before the Covid-19 outbreak.

These methods include dividing the passengers into several zones, with the business class boarding first followed by different zones.

Study author Dr Ashok Srinivasan, of the University of West Florida in the US, said that random boarding is better than either back to front or other methods that were being used by airlines in the US prior to the Covid-19 outbreak.

He said: “It should be OK if the passengers are prioritised into certain groups, such as frequent fliers, but the main focus ought to be on avoiding a process that boards a large number of people sitting close to each other at the same time.”

Dr Srinivasan said that banning the use of overhead storage bins can lead to around a 60% reduction in exposure to the virus while boarding window seats before aisle can result in 33% decrease in exposure.

He added: “Keeping middle seats empty can decrease exposure during boarding by 50% but of course, due to the cost involved, it may not be economically attractive.”

A combination of all the strategies, Dr Srinivasan said, could result in up to 90% reduction in exposure to coronavirus.

He also added that using medical-grade masks, such as FFP2 or N95 respirators, “could almost eliminate infection risk during air travel” but added, it would require passengers to “keep them on throughout, which means they cannot eat on the plane”.