Norvel puts a screen mesh over some of their engines,, but there is generally not much in the air thats gonna get in your engine because of the propwash,, and it wouldnt merit the performance problems that you'd have for the small amount of time its running on the ground during take off or landing,,I just stuck a small engine in about 5 inches of good ole North Carolina red clay last week,, an air filter would have just been knocked off on the way in..you need one on a car but not a plane, I suppose you could adapt certain foam ones but it would be more trouble than it would be worth........except maybe the beach or the desert.....Rog