“Between an airplane and every other form of locomotion and transportation there is one great contrast. The horse and wagon, the automobile, the bicycle, the locomotive, the speedboat, and the great battleship—all can come to a standstill without danger, and they can all reverse their engines, or their power, and go back.
But there is no reverse about the engine of an airplane. It cannot back up. It dare not stand still. If it loses its momentum and forward-drives, then it crashes. The only safety for the airplane is in its forward and upward motion. The only safe direction for the Christian to take is forward and upward. If he stops, or if he begins to slip and go backward, that moment he is in danger.”—C. E. Macartney