Fly enough and you’ll eventually have the uncomfortable “eeeew” moment of when you open a tray table and are greeted by a nice fresh ring of dried coffee. Unlike roadside diners where you can avenge yourself with a scathing Yelp review, in a 737 all you can do is wonder, uselessly, “Wait -- how often do they actually clean these things?”
Airplanes are notorious for being giant flying petri dishes. The rush to turn flights around in mere moments, day in and day out, makes them akin to a bath towel you always air-dry but never wash. The FAA has nothing to say about how often and how thoroughly planes are cleaned, so the airlines are in charge. Guess where that leaves you. When Skytrax rated the 20 cleanest airlines in the world this year, EVA Airways was tops, but no US carriers made the list. But how dirty is dirty, exactly?