green air
n.— «It’s a surreal view of the world, flying with night-vision goggles, and some pilots and crewmen refer to it as taking off into “the green air.” In fact, Cantu and his fellow B Company, “Hill Climbers” see more green air than they do daylight.» —“Chinook pilots, crewmen spend their nights flying in ‘the green air’” by Monte Morin Stars and Stripes Nov. 25, 2006. (source: Double-Tongued Dictionary)