Met this fellow on a recent trip as he was headed to a family reunion in Germany. He's missing out: we had one in Twin Falls, ID and it was awesome.
His face was just screaming to be photographed. His eyes were bright and intelligent. The trick with airplane portraits is timing. Some folks are a bit cranky with hustling to the airport and are more amiable after a little nap. Others are nervous and talkative and will do anything to keep their minds off the takeoff. One Gal chatted with me half way across the country and let me shoot about thirty frames as we tried to get the arrangement right (it's tough when you're holding the camera against the seat in front of you guessing where to point). Actually the real trick to airplane portraits is getting the emergency exit so you have room to maneuver.
Nikon D90, 35mm lens, f/2.2, 1/100s, ISO 200. Soft light from windows is great on all planes--sure beats trying to shoot through dirty windows to the world outside!