. . . bleed air leaks, engine exhaust, hot hydraulics, fuel, swamp ass and farts. Ah, the good ol' days(?).Military aircraft have a distinctive smell, and when you have been around them for a hot minute you can differentiate by sound. One of the many things I miss about growing up in eastern NC (New River MCAS, Cherry Point MCAS, Seymour Johnson AFB all within about 75 miles), and certainly flying as air crew.