Could airline boarding procedures contribute to the spread of communicable diseases? New research indicates they might.
Researchers at Arizona State University examined how boarding practices and aircraft size influence transmission risk. Their findings indicate that routinely bringing together passengers from varied locations and keeping them in close proximity for extended periods creates opportunities for infectious diseases to travel with air travelers.
One common boarding method—loading passengers from front to back—can exacerbate the problem. This approach often creates aisle bottlenecks where people stand shoulder to shoulder while stowing luggage and finding seats, increasing close contact and potential exposure. The ASU team found that alternative practices, such as dividing a cabin into two longitudinal sections and allowing passengers to take seats at random within those sections, can reduce these crowding points and lower the chance of disease spread during boarding.
“Surprisingly, changing policies — even those as simple as boarding patterns — can have a significant impact on the global spread of an infectious disease,” said lead researcher Anuj Mubayi, assistant professor in ASU’s School of Human Evolution and Social Change.
The study also highlights aircraft size as an important factor. Smaller planes—those with roughly 150 seats or fewer—present a lower transmission risk, in part because they typically carry fewer potentially infectious individuals and because boarding and deplaning occur more quickly, shortening the period of close contact among passengers.
“Using smaller airplanes during an outbreak, instead of completely banning flights to a specific destination, can drastically reduce the probability of introduction of infection,” Mubayi added. By reducing passenger density and minimizing the time spent in crowded aisles, airlines can lower the likelihood that an infected traveler will transmit illness to others on board.
These findings suggest that modest adjustments to boarding strategies and fleet deployment could serve as practical, less disruptive measures during infectious-disease outbreaks. Rather than resorting immediately to blanket travel bans, airlines and public-health authorities might consider boarding protocol changes and temporary use of smaller aircraft to limit transmission risk while preserving essential travel and connectivity.