The Road to the Future… Is Paved With Good Inventions
We bring you 10 great ideas that made flying safer, easier, or just a whole lot more fun.
- Air & Space magazine, September 2009
NASM (SI 76-17595-P)
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In August 1975, during the Experimental Aircraft Association’s annual celebration of homebuilding in Oshkosh, Wisconsin, N4EZ, powered by a Volkswagen engine and piloted by Rutan’s brother, Dick, set a closed-course distance record by flying 1,638 miles without landing. The airplane caused such a sensation that the following year, when Rutan issued the plans for the VariEze, a greatly modified design that accommodated a heavier engine, he sold 100 sets the first day. Over the next three years, he sold 4,500.
“Rutan’s great innovation,” says Russ Lee, a curator of aeronautics at the National Air and Space Museum, “was simplifying the basic construction process. He saved homebuilders hundreds of hours of cutting out pieces of wood.”
Before the VariEze, homebuilders needed skills in woodworking and, often, metalworking. Rutan’s customers built the VariEze by using a hot wire to cut foam in the shape of the full-size templates that came with the plans. They then covered the pieces and joined them with high-strength epoxy and sheets of fiberglass.
The VariEze builder’s manual opens with Rutan’s manifesto: “It is our intent to drastically reduce the non-completion rate common to homebuilt aircraft.” Sprinkled with cartoons, the directions in the manual have an easygoing, conversational tone. Each step is accompanied by an estimate of the time it should take, which does not include “discussing your workmanship with friends that stopped by to help.” Rutan’s inspiration? Simplicity dress patterns. He says, “If you buy a pattern to make a dress, what you see there is a sketch, and then a sentence or two or three, and then another sketch, and they just walk you through building this dress.”
Of course neither the construction process nor the directions would have mattered had Rutan’s aircraft not looked so singular or performed so well. It is designed so that as soon as the canards stop producing lift, at a certain angle of attack, the airplane automatically noses down sharply. The nose-down attitude keeps the main wings from stalling and makes the aircraft virtually stall-proof. Its winglets — the VariEze was the first aircraft to fly with them — decrease drag, boosting climb rate and cruise speed.
The VariEze carries its engine in the rear, where it drives a pusher propeller. To keep the weight of the engine from tipping the parked aircraft backward and damaging the prop, Rutan created one of the aircraft’s more exotic features: a nose gear that the pilot retracts after parking, enabling the VariEze to bow. Worried about scuffing the nose, Rutan suggested that builders affix some type of bumper under it; he used a hockey puck.
By 1985, Rutan had sold 12,000 sets of plans for the VariEze and its bigger, better performing brother, the LongEZ, which Rutan calls “my best homebuilt.”
Some have suggested that the force was with Rutan in 1975, before the movie Star Wars spread it to the rest of the world. The film was released in 1977, the first full year the VariEze plans were sold, and many see a resemblance between the dashing X-fighter spacecraft that George Lucas created for the screen and the otherworldly VariEzes that were proliferating at small airports across the country. The VariEzes don’t have the “X” configuration and aren’t propelled by whatever exotic method the X-fighters use, but they do have one thing in common with the movie-star airplanes: Thirty-four years later, they still look like the future. (Read our recent interview with Rutan.)
A Little Extra Oomph
When the u.s. air force and the National Advisory Committee for Aeronautics started exploring high-speed flight with the Bell XS-1 in 1947, off came the lid of a Pandora’s Box of aerodynamic woes that had only been hinted at as piston-engine aircraft approached transonic speeds. In October, shortly before achieving Mach 1.06, Chuck Yeager found that as he neared the speed of sound, the XS-1 would no longer respond to control inputs. “I pulled back on the control column,” he told an interviewer for the PBS series “NOVA” in 1997. “Nothing happened. The airplane just went the way it was headed.” Like the gremlin that roamed the wing in “The Twilight Zone” episode “Nightmare at 20,000 Feet,” a shock wave had taken up residence along the horizontal stabilizer, preventing the two small elevators on the stabilizer’s trailing edge from fully responding to pilot input.
Yeager and the rest of the team thought that if the entire horizontal stabilizer rather than just the elevators could be made to move up and down, the “all-moving tail” might be able to win the arm wrestle with the shock wave. Thanks to the NACA design team at Virginia’s Langley Aeronautical Laboratory, the XS-1 had been equipped with just such an adjustable stabilizer — a sort of gigantic trim tab. The XS-1 team set to jury-rigging a fix. “Being a mechanic, all we did was squirt 3-in-1 oil on it and run it up and down, up and down, until it worked,” Yeager said.
On October 14, after the B-29 mothership released the XS-1, the bullet-shaped aircraft reached 94 percent of the speed of sound at 42,000 feet. “I just cranked the leading edge up on the horizontal stabilizer to keep the nose down,” Yeager said. “All the buffeting smoothed out, because the supersonic flow went over the whole airplane.” Then a boom echoed over the high desert: The XS-1 had exceeded the speed of sound.
And that’s what it took to crack Mach 1 without the inconvenience of a catastrophic structural failure. Today, all supersonic aircraft wear all-moving tails.
Today, most fixed-wing aircraft carry a device that dates back to the insights of one man: Leonard Greene.
Early on, Greene worked as a chemist but pursued a passion for flying. According to family accounts, one clear day in 1937, the 19-year-old was preparing to take a flying lesson at an airport on New York’s Long Island when an aircraft on approach suddenly plummeted to the ground. The pilot was killed. Having witnessed the tragedy, Greene set about learning what caused it.