Even to pilots, the 1903 Wright Flyer is a mysterious bundle of wire and cables that has little in common with today’s aircraft. But look more closely at how the machine flies and you begin to see the connections. Crawl over the wing, settle into the hip cradle, and discover the Wrights’ ingenuity in identifying and controlling the complex forces that act on an aircraft in flight.
Climb in facing the two-surface horizontal elevator. On modern aircraft the elevator and rudder are combined in the tail, but here they are separated: elevator in front, rudder behind. The two elevator surfaces generate lift. They also provide a handy reference point to the horizon, and give the prone pilot some protection in the event of a crash.
The Wrights reasoned that a prone figure piloting the aircraft would create slightly less drag than a seated pilot. You may eat a few mouthfuls of sand on the rougher landings, but that’s a small price to pay for flying the world’s first airplane. You have half a gallon of fuel on board, enough to fly for 20 minutes, but your neck will start to ache long before your fuel runs out.
Start the engine, which is at your right, offset from center, by moving the horizontal lever at your right hand to the center position. This opens the cock connecting the fuel line to the engine. Simultaneously, assistants will pull the propellers through in unison. The two propellers, mounted at the rear of the wings, rotate in opposite directions to cancel torque, which tends to pull an airplane in the opposite direction of its propeller’s rotation.
A small truck made with the hub of a bicycle wheel supports the craft in the rear; another hub is affixed to the craft at the front. With the engine running and the propellers turning, an assistant releases the restraining wires and you roll on the hubs along a single rail. With the required 20-knot wind on the nose, you will lift off in about 40 feet. Your left hand rests on the elevator control, a small lever attached to a rod running along the leading edge of the lower wing. Pull back slightly on the lever and the connecting rods tilt the elevator assembly in front of you slightly up, creating enough lift to urge the wings upward. (The elevator is very sensitive; use small motions.)
Other aviation visionaries attempted to control flight in only two axes: pitch—nose up and down, and yaw—nose side-to-side. The Wrights were the first to understand the third: roll. Their patented wing-warping system controlled the Flyer’s movement around its longitudinal axis. Sliding the hip cradle deflects the edges of the wings’ outboard sections and causes the airplane to bank. The center section of the airplane stays rigid as a stable platform for the propeller shafts and transmission chains.
The braided cable attached to the hip cradle zigzags through pulleys placed about two-thirds of the way back along the rear wing struts. When you slide the hip cradle to the right, the cable pulls the right wing tips down and the left wing tips up. The left wing tips, with their increased angle of incidence, generate more lift. The left wings rise as the right wings, with their lift decreased, fall. The airplane rolls to the right.
In the roll, the left wings, with their increased lift, also develop correspondingly increased drag. That makes the left wings fall slightly behind the right wings, pulling the nose to the left as the airplane rolls right. The Wrights corrected for this “adverse yaw” by connecting the rear rudder to the wing-warping system. As the airplane rolls to the right, the interconnected cables pivot the rudder so that its trailing edge points right. Acting as an airfoil, the rudder generates enough lift to resist the yaw caused by the slowed left wing, holding the airplane so that the nose continues to point right.
At the end of the flight, you land in the sand on the skids on the Flyer’s underside. Most landings break something on the airframe. No matter, the simple ash-and-spruce frame can be repaired much more easily than today’s aluminum or fiberglass fuselages. After a day in the shop, the Flyer will be ready for another few minutes of flight.