Yet the problem of perfectly controlled flight under all ordinary conditions was by no means completely mastered. The principle was correct, but there were endless details to be worked out. The embodiment of these is the Wright flying-machine of the present time.
In the Wright aeroplane the lifting power is obtained by two parallel horizontal planes of canvas stretched over retaining-frames, placed with their long diameters transversely to the direction of flight, as in the case of the wings of a bird. At a little distance, in front of these, are placed two horizontal parallel rudders, and at the back two parallel vertical rudders. The machine is mounted on huge skids, which resemble giant sled-runners in shape, but lighter and more flexible, and is driven by two wooden-bladed propellers not unlike some of the types of ship-propellers. For stability in flight under all kinds of atmospheric conditions this machine has shown itself to be a true flying-machine, capable of navigating the air in any direction at the will of the operator, and remaining in flight a length of time dependent entirely upon the amount of fuel carried.
The stability of this machine, particularly in a transverse direction, has proved far greater than that of any of its predecessors or contemporaries. The two horizontal rudder-planes mounted in front maintain the fore-and-aft stability; while keeping the machine on an even keel is accomplished by varying the angle of incidence by warping the two main planes,--this being, indeed, a vitally important feature of the mechanism. In this manner a greater lift on the low side and a diminished lift on the high side is obtained, this being maintained manually, as is the fore-and-aft stability. Since the warping of the wings of the machine would tend to deflect it from its course, the apparatus is so arranged that a single lever controls the flexible portion of the wings and the vertical rudder, the motion of the latter counteracting the disturbing influence that would otherwise result from the twisting of the wing-tips. The discovery of this combination gave the finishing touches to the aeroplane, and made it a manageable mechanism. In other words, it made the flying machine a machine in which man could fly.