You might have heard this quite a few times before as well from some people but probably might not have given much thought to it. The fact is however absolutely correct. It’s a universally accepted truth of travel that airplanes are often nasty, germ-filled, places.
If you are boarding a plane that has had a short turnaround from its previous flight, is not very clean at all. While a cleaning crew does board the aircraft, if that plane needs to be back out of the gate in around half an hour, the crew is only going to be able to tackle the big, most obvious messes.
Giving the seats a decent clean, however, is still not within the crew’s scope. For that, they have to wait until the plane is parked overnight, where galleys and lavatories get a thorough cleaning, waste is removed, and blankets and pillows are replaced.
Hence, it is advisable to check the seat before grabbing it. Protecting your nose and mouth with kerchief to prevent inhaling of germs and communicable bacteria. Keep a hand sanitiser and a pack of medicated wet tissues handy.