- Historic Sites
The First To Fly
June 1970 | Volume 21, Issue 4
Meanwhile, they went to work on the ribs and spars for the wings of their next machine. They had already decided to make it bigger than anything they had tried before. The wings were to be 40 feet 4 inches long and 6 feet 6 inches wide. Instead of making the larger wing ribs out of one solid piece of wood they made them out of two thin strips with the long spars sandwiched in between in order to save weight. They also conducted wind tunnel experiments to see what shape they should use for the struts and braces to cut drag to a minimum. To their surprise a square cross section with the corners slightly rounded off proved to be the design that would slow down their aircraft the least.
Propellers to drive the new craft were expected to present little trouble. Since 1816, when the British experimenter Sir George Cayley thought of the idea of using them on steerable balloons, propellers had become part of the design of every powered aircraft, fanciful and otherwise, that had been seriously advanced, except for the flapping wing, or ornithopter, variety. The only difficulty was that none of the Wrights’ predecessors, including Langley, seemed to understand what the problems were when they designed their propellers. Consequently, the Wrights soon discovered that all the previous designs were little more than windmills of various sizes and shapes that beat the air ineffectually, generating little thrust, or pull, despite the horsepower that made them turn. Again they were forced to work out a theory of their own.
From the first the Wrights realized something that previous experimenters had missed. For decades seagoing ships had been pushed through the water by the action of the rear surfaces of their propellers shoving the water behind them. But the Wrights reasoned that aircraft propellers would have to behave differently. They felt that the propeller should be designed like a set of whirling wings in which the forward surface, like the top surface of a wing, developed lift—or in this case, thrust—along the aircraft’s flight path.
This piece of reasoning was every bit as important as the thinking that had produced the wing-warping idea and the movable rudder concept of 1902. But the Wrights were in a hurry now. There was much to do before the next summer and too little time to devote to recording the mental process by which they grasped a fact that had eluded many others. So they simply jotted down in a notebook the results of two tests, worked out a formula on the basis of this data that enabled them to predict propeller performance with amazing accuracy, and then made themselves a pair of propellers consisting of three pieces of carved spruce laminated with glue. Rough shaping was done with a hatchet. The brothers used a drawknife to whittle the blades to the final degree of precision.
It was almost the end of September before all was packed up and ready for the return to Kitty Hawk. The Wrights were aware from the newspapers that Langley was about to make his first attempt at flight with his big man-carrying machine, but they weren’t particularly concerned. Earlier, Wilbur had even expressed some doubt that the Langley machine would work. “Prof. Langley seems to be having rather more than his share of trouble just now with pestiferous reporters and windstorms,” he commented^in a letter to Chanute. “It would be interesting to attempt a computation of the possible performance of his machine in advance of his trial, but the data of the machine as given in the newspapers are so evidently erroneous that it seems hopeless to attempt it.…”
As October wore on at Kill Devil Hills, the clear days and steady winds prevailed that were ideal for glider flights with the 1902 machine. Instead of going for distance, the Wrights added a new twist to their glider work and began trying to see how long they could remain airborne by “soaring.” By this they meant taking off into a wind strong enough to sustain them in a hovering position a few feet from their point of take-off. In previous summers at Kitty Hawk they had marvelled at the ability of buzzards and hawks to do this and had spent many hours watching them hover almost motionless above the dunes. Orville finally set the record with a flight of 1 minute 11 4/5 seconds. This, of course, was a world record —and one which stood unchallenged until October 24, 1911, when Orville again broke the record, with a soaring flight of 9¾ minutes. The 1911 record was not broken for ten years.
Meanwhile, the new aircraft that would soon change history was beginning to take shape. By October 15, with the assistance of their friend George Spratt, the Wrights had completed the upper wing and covered it with cloth. Another friend sent them a sobering account of Langley’s first disastrous attempt at a man-carrying flight, and Wilbur commented in a letter to Chanute: “I see that Langley has had his fling and failed. It seems our luck to throw now, and I wonder what our luck will be.”
The transition from glider to powered flying machine was a tremendous step; the 1903 airplane reflected this in almost every detail. The pilot was still going to lie prone on the bottom wing, but when he was stretched out like this, the only place for the engine was to one side of him. However, the engine weighed thirty-four pounds more than either potential pilot; thus the airplane was unbalanced. The Wrights corrected this by adding four inches more to the wing on the heavy side to create additional lift.