The Airplane - Jay Spenser [19]
Cayley’s formula is not the only way to lay out a working airplane, as countless unconventional designs have attested over the decades. Nevertheless, the fact that his 1799 configuration has predominated from World War I to the present day shows just how presciently he identified for us the best configuration.
Seven years after Lilienthal’s sacrifice, the Wrights succeeded at Kitty Hawk. But how they did it, and what their would-be competitors were doing in Europe, tells us that in this brief span, Cayley’s guidance was temporarily forgotten. How do we know this? From the sheer variety of airplane layouts that experimenters were wrestling with at the start of the twentieth century. This configurational uncertainty is in fact the defining feature of flight’s emergence.
The Wright 1903 Flyer has wings, an engine, propellers, and movable surfaces that deflect for control in flight. What the Kitty Hawk Flyer doesn’t have is a fuselage. Yes, history’s first airplane is all wing and no body, and that’s not all that’s odd about it. The Flyer also has skids instead of wheels for an undercarriage, and its elevator is at the front rather than the rear, where Cayley said to put it. Almost all airplanes since the Wrights have had rear elevators, of course.
These three configurational choices—landing skids, a forward elevator, and especially the lack of a fuselage—explain why the Kitty Hawk Flyer and its successors look strange to us today. But the Wrights had reasons for going this unconventional route.
Recognizing weight as an enemy of their efforts, they decided to identify and incorporate only those elements specifically needed for success. This they achieved through a rigorously scientific process combining observation, experimentation, quantitative analysis, and critical thinking. So unerringly did they succeed, and so highly optimized are the Flyer’s technical elements, that Wilbur and Orville rank as engineering geniuses—they were true scientists, not tinkerers.
To keep weight to a minimum, the brothers selected a biplane wing structure as the heart of their airplane. Developed by their mentor, Octave Chanute, these biplane wings in turn exploited the 1893 invention in far-off Australia of the box kite, a new type of kite that bound parallel wings tightly together to create a rigid structure. While many kites dating back to antiquity had featured parallel wing panels, Hargrave and Chanute were the first to bring the insights of modern engineering to their construction.
In one fell swoop, this breakthrough kite technology eliminated the need for a fuselage by making the Flyer’s wings—braced together with struts and wires—the airplane’s skeleton. Having gone this route, the Wrights considered a fuselage superfluous and dispensed with it.
The lower wing provided space for a pilot to lie prone, and a pair of goggles sufficed for protection from the elements in a machine that would fly no faster than a horse gallops.
Had Wilbur and Orville instead followed Cayley’s lead in terms of configuration, they might have come up with a more refined design with greater development potential and a longer presence on the world stage. Their airplanes might also have been easier to produce in number, a failing of the Flyers. However, the brothers would most certainly not have untangled aviation’s challenges so quickly.
The configuration adopted by the Wrights has often been dismissed as lacking or backward. The brothers did fine elsewhere, critics say, but they failed to come up with a modern layout. However, this misses the point.
Imagine you’re trying to solve the many puzzles of heavier-than-air flight using materials, technology, and knowledge available to you at the close of the horse-and-buggy era. Remember too that you need ready access to all parts of your