Our biggest weather problem during the late fall and for most of the migration is moisture. If the temperature is cold, the moisture produces frost.

Why is frost on the wings a problem the pilots must solve? A wing requires a smooth flow of air over the top surface to produce lift. Frost makes the wing surface rough. This breaks up that smooth air flow, destroying the lift. The thicker the layer of frost, the less lift the wing can generate and the faster we must fly to stay airborne. It only takes a few crystals before we are too fast to lead birds, and only a thin layer before the airplane won’t fly at all.

Ultralight airplanes get new covers.
Photo: Operation Migration