Features  / 02.13 /

Control freaks

How airplanes got this way

curtiss jenny

There’s no use lying about it: Learning to fly takes some coordination. The more coordinated you are, the better you fly—at least by the seat of your pants. But don’t get whiney; you don’t have to shift your weight to control the trainer like Otto Lilienthal did with his gliders in the late 1800s. And you don’t have to invent the mechanical system itself—then teach yourself how to use it—as the Wright brothers did. And you also don’t have to adapt to several systems, like pre-World War I air corps fliers did. Yeah, you’ve got it easy.

After Lilienthal died in a glider crash because his weight-shifting system wasn’t perfect, the Wrights (who figured powered flight was already on its way) became interested in controlled flight. In order to reduce drag on their early gliders that they tested at Kill Devil Hill, the brothers lay on their bellies on the bottom wing. To control its pitch, they mounted a short lever just in front of their right hand that changed the position of the elevator. Pulling it back made the glider rise; pushing it forward made it descend. That was the no-brainer. But keeping the wings level kept them up nights.

Since they lay on their bellies like reptiles, they decided to use a cradle, which, when shifted by moving their hips, operated the wing warping (their version of ailerons) and moved the rudder, because they linked it to their version of ailerons—the wing-warping mechanism. Shifting the cradle to the right made the right wing drop and the rudder move right, turning the nose right; shifting it to the left made the left wing drop and the rudder move left, turning the nose left. It worked so well that they built it into the 1903 Flyer. And so, on December 17, 1903, the brothers made the first of four powered, controlled flights: The initial one was 120 feet in 12 seconds; the last, and longest, was 852 feet in 59 seconds.

That’s barely long enough to cramp your neck when you’re holding your head up to see where you’re going.

er coupe adThe 1903 machine was destroyed that day by a gust of wind; the 1904 machine was an abject failure that barely got off the ground. But the 1905 machine was a good one. It could circle, fly figure-eights, and it could stay in the air long enough to send severe pain shooting down the brothers’ necks.

By 1908 the Army realized it was interested in flying, and the brothers promised to deliver a machine with a 50-mile range that could carry a pilot and a passenger. To sweeten the deal they promised to teach a few officers how to fly it. Before demonstrating a flying machine—which they also promised to do—Orville set about reconfiguring the 1905 bellybuster into an upright two-seater with dual controls. And not a moment too soon. “I used to think that the back of my neck would break if I endured one more turn around the field,” Orville said. The control system the brothers devised consisted of three levers: two (on the pilot’s left and the passenger’s right) controlled the elevator; the third, between the seats, controlled the wing-warping mechanism. To operate the rudder (which the brothers had decided functioned better when it wasn’t linked to the wing-warping mechanism), they mounted a twist grip for the top of that lever.

Sound confusing? It was. You really had to think about it, especially when you learned it one way as a student, then were trained as an instructor and learned to operate it the opposite way, and then had to explain what you were doing to your student. Even writing that sentence gets confusing.

Meanwhile in New York, Glenn Curtiss began building machines in which he controlled pitch with a steering wheel mounted on a lever, and he sat encased in a shoulder-high yoke that operated the ailerons when he moved from side to side. In France, a gentleman named Robert Esnault-Pelterie stole the Wrights’ wing-warping system for his REP, which he manipulated with a broomstick mounted on a universal joint on the machine’s floor. Moving the broomstick side to side operated the wings; moving it forward and backward operated the elevator. The REP would have flown perfectly if it weren’t for a lousy engine and no rudder to speak of. A short, stout Frenchman named Louis Blériot adapted Esnault-Pelterie’s system for his eighth machine—named, surprisingly, Blériot VIII. Unlike the Wrights, Blériot barely had to think about controlling the Blériot VIII, although it and the two subsequent ones didn’t fly so great. Then he got to the Blériot XI. In 1909 he flew it across the English Channel, an event that captured the world by storm, and in no time 100 people ordered his airplane. One order came from as far away as Wichita, Kansas, placed by Clyde Cessna.

So those were the three main control systems developed before World War I. When the war erupted, thousands of pilots from several nations needed to be trained to fly thousands of machines built by dozens of manufacturers. For most of those machines the relatively ubiquitous little Blériot XI became the pattern, from the engine in front, the tail in back, and the simple stick-and-rudder-bar system in the cockpit. Even Curtiss adopted the system for a trainer, the Curtiss Jenny. With the Jenny, the instructor could perform a maneuver, and the student could follow along. The Wrights never did change their system, but by then they had stopped building airplanes.

There are minor variations on the stick-and-rudder pedals. There were yokes, of course, and the World War II-era ERCO Ercoupe, which had its rudder and ailerons linked together like the Wright Flyer. So simple, anyone could learn to fly. But not everyone should learn to fly.

A couple of years ago I flew a two-seat F–16 with a pilot who was discontented because he was stationed stateside instead of in Iraq, so he let me buzz around the desert and mountains near Edwards Air Force Base to my heart’s content while he just went along for the ride. Like many new airplanes with computer controls, the F–16 comes equipped with a sidestick, a grip mounted on the cockpit’s right side. Like the Blériot system, but even more so, all I had to do is think about a maneuver—a roll, loop, or dive, say—and the airplane did it. Yup, the system is an improvement over Louis Blériot’s, and nothing like the Wrights’.

Phil Scott is a freelance writer living in New York. His latest book is Then and Now: How Airplanes Got This Way.