Kennedy said planes are usually de-iced within 30 minutes of an airplane's takeoff. In some cases there is a unit at the end of the runway to de-ice planes moments before takeoff, he said. Once the planes are in the air, there are other multiple methods used to keep ice from forming on the plane. This method is similar to what we do when we put chemicals on our car windows to keep ice from forming. There are also heated wings that will blow hot air over the wing.
Some planes have neoprene boots, or boots covered with rubber, that can be inflated with air.
The boots are located at the leading edges of the tail and wings. Kennedy said that, nowadays, there's no reason to be preoccupied about danger due to the weather conditions of that holiday flight.