Shooting through an aircraft window is really tough, because you get ugly reflections unless you're very careful; these reflections always seem to be much more obvious in the photos than you thought they would be at the time of shooting. A big help is to use a flexible rubber lens hood and press it against the window to keep stray light out (a rigid hood is no good, since it won't seal against the window well and will transmit plane vibrations to the camera). It also helps to be very selective of the direction you're shooting, with the sun behind you (not just to the side, which isn't good enough). It would be wise to get a rubber lens hood and practice taking photos through your car window on a sunny day before you go.
Lisa