Though the airlines hit record lows during the height of the coronavirus pandemic this past spring (according to the Bureau of Transportation Statistics, air travel was down 96% from last spring) more people are starting to fly again. Though the CDC continues to recommend people to stay at home, some people have to fly right now.
Of course, the airlines are trying to do everything they can to keep passengers safe and healthy (masks have required the duration of most flights) but some things may be out of your control like staying six feet apart from other passengers and where you sit. Though sitting in the aisle seat sounds like a smart move, during a pandemic it is actually the worst place to sit.
According to a 2018 study published in Proceedings of the National Academy of Sciences that looked at the behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights, the aisle seat is the absolute worst. The research was conducted by the team who took 10 flights between 3.5 and 5 hours, predominantly on Boeing 757 aircraft, from Atlanta to five destinations on the West Coast.
Because you are sitting in the aisle you tend to move around more. Eighty percent of passengers in aisle seats moved around during flights while it was only 60% for people in the middle seats and 40% for those in the window seats.
Since many airlines are not selling middle seats and they may not even exist soon (or will look very different) the one you want to opt for is the window seat. Window seat passengers average of 12 contacts per flight compared to middle seat users (58) and aisle seats (64).
Luckily transmission risk on a flight is quite low (unless you are sitting in the same row as someone who has COVID-19) but if the flight attendant has the infection then the risk goes way up since they move around so much and especially in the aisles.