It had been 7 years since the Wright Brothers flew the first plane, and Charles Hamilton was about to make the first round trip flight from New York to Philadelphia. In this article, he provides a very plain-language explanation of exactly how his plane works.
Driving an aeroplane at the speed of 120 miles an hour is not nearly as difficult a task as driving an automobile sixty miles an hour…
In running the automobile at high speed the driver must be on the job every second. There are constant opportunities of encountering obstacles. For instance, a man can never tell at what moment he is to encounter some vehicle, perhaps traveling in the opposite direction. Nothing but untiring vigilance can protect him from this danger. Then there are turns in the road, bad stretches of pavement, and other like difficulties. All these require the same attention.
But in an aeroplane it is an entirely different proposition. Once a man becomes accustomed to aeroplaning, it becomes a matter of unconscious attention. For instance, let me give you as an example the bicycle. Nearly every one has at some time or other ridden one, and these can appreciate my point. They will remember how, when they first mounted the wheel, maintaining their equilibrium was a matter of nerve-racing vigilance. In their efforts to maintain it they would invariably put the wheel too far to the falling side. Whenever they saw an approaching vehicle they felt a moral certainty that they would be run down, and in order to avoid this catastrophe would make ridiculously wide detours, but a little practice and the equilibrium was unconsciously maintained. They were soon riding without the use of the handlebars maintaining their poise simply by an unconscious shift of the body. Approaching vehicles became an equally simple problem.
Now, that is exactly the situation with an experienced aviator.
He may have been an experienced aviator, but he wasn’t a good prognosticator. He says:
For my part, I do not believe that there will ever be an automatically controlled aeroplane. Such a contrivance would tend to drive an aeroplane through counter air currents, and the machine would be hopelessly ripped to pieces. They will get an automatic control for an aeroplane when they devise a pair of eyes for an automobile that will guide it down Broadway without collision.”
It actually didn’t take very long before autopilot was in common use. In 1931, an aviator set a record for flying around the world in just 8 days. He used autopilot to steer when he needed to rest.
CHARLES K. HAMILTON TELLS HOW TO RUN AN AEROPLANE: The Intricate Mechanism of His Biplane Explained in Detail Showing the Uses of Every Part (PDF)
From June 12, 1910