One explanation for the apparently low risk level is that the air in modern aircraft cabins is replaced with new fresh air every two to three minutes, and most planes are fitted with air filters designed to trap 99.99% of particles.
Meanwhile, various new protocols have been implemented, such as face-coverings for both passengers and crew, which is mandatory on most airlines, temperature screenings, as well as more intensive cabin cleaning and limited movement in the cabin during flight.
Arnold Barnett, a professor of statistics at the Massachusetts Institute of Technology’s Sloan School of Management, tried to quantify the odds of becoming infected with the virus while on board a short flight in a recent study that looked at the benefits of the empty middle seat policy.
According to his findings, based on short haul flights in the US on aircraft configured with three seats on either side of the aisle, such as the Airbus 320 and the Boeing 737 — and assuming everyone is wearing a mask — the risk of catching the virus on a full flight is just 1 in 4,300. Those odds fall to 1 in 7,700 if the middle seat is vacant.