“The pilot in an observation plane is, in one sense, the chauffeur. On account of the fact that communication between the pilot and the observer is ordinarily very poor, we refer to the pilot as the horse, for he must be guided, and for that reason we append to his arms directly under the armpits two pieces of twine, string or cord which we extend back to the observer. The observer holds the reins. The observer is given the mission to perform and, while he expects the utmost voluntary coöperation of the pilot, when it comes to any matter of tactical decision the observer’s word is final; for instance, in this flight, should we see five planes and decide to attack them, I would simply give the word and you would direct the plane toward them; or if we are attacked by them I would give the word whether to dive toward the ground and run from the enemy or stay and fight it out; or should I see a machine gun nest on the ground which was holding up our advancing troops, should I decide to go down and destroy that machine gun nest it is your duty to direct your plane down on the machine gun nest even though you know it is certain death. The observer points out the direction in which he wants to go, how long he wants to stay there, how long he wants to stay at the line, and, in fact, is the commander of the plane. As I said before, he is the holder of the reins. “Now, there is only one exception to this, and that is when something is mechanically wrong with the airplane. For instance, if the engine is failing or if a strut is broken, or if flying wires are destroyed—in such a case the pilot becomes responsible for the command of the plane. The fear of failing to hear clearly the directions given by the observer through the speaking tube is the reason we have the lines to guide the pilot like a horse, and when the observer wants to go up he points up and when he wants to go down he points down; and should he want to go to a certain place he would point to that place. It is a sort of mental telepathy which is expressed in a sign language and is ordinarily easily understood, so don’t worry—just pay close attention and don’t lose your head and you will get along all right, for after all, flying over the front is not so full of thrills as one ordinarily is led to believe, and whether you live over your allotted twenty hours over the lines depends largely upon your ability and good luck and watchfulness.”