[CHAPTER IX]
The Navigation of Aircraft
I do not claim to be an especial authority on the theory of navigation—indeed, it was as a prisoner of war that I first took up seriously the study of that science. But I believe that sustained and sufficient concentration can give a man what he wants; and on this assumption I decided to learn whatever might be learned about navigation as applied to aircraft. As yet, like most aspects of aëronautics, this is rather indefinite, although research and specially adapted instruments will probably make it as exact as marine navigation.
Navigation is the means whereby the mariner or aviator ascertains his position on the surface of the earth, and determines the exact direction in which he must head his craft in order to reach its destination.
The methods of navigation employed by mariners are the result of centuries of research and invention, but have not yet reached finality—witness the introduction within the last few years of the Gyroscopic Compass and the Directional Wireless Telegraph Apparatus, as well as of improved methods of calculation.
In short journeys over land by aëroplane or airship the duties of a navigator are light, so long as he can see the ground and check his progress towards the objective by observation and a suitable map.
But for long distance flights, especially over the ocean and under circumstances whereby the ground cannot be seen, the navigator of the air borrows much from the navigator of the sea. He makes modifications and additions, necessitated by the different conditions of keeping to a set course through the atmosphere and of keeping to a set course through the ocean but the principles underlying the two forms of navigation are identical.
It is impossible to explain aërial navigation without seeming to paraphrase other writers on the subject. One of the simplest explanations of the science is that of Lieutenant Commander K. Mackenzie Grieve in "Our Atlantic Attempt," which he wrote in collaboration with Mr. Harry Hawker, his pilot, after their glorious attempt to win the London Daily Mail's transatlantic competition.
The chief differences between the navigation of aircraft and the navigation of seacraft are occasioned by:
(a) The vastly greater speed of aircraft, necessitating more frequent observations and quicker methods of calculation.