Wingspread: Celebrating the Centennial of Flight
Chuck Yeager's history-making trip across what was once called the "Sonic Wall" almost never happened. Because his tail wouldn't fly.
But with the help of a band of mechanical engineers- and one certified scientist-Yeager and his compadres managed to succeed against great odds.
Chuck Yeager was a young Army Air Forces Captain in 1947. The National Advisory Committee for Aeronautics (NACA) had been test flying a research plane called the XS-1. Built by Bell Aircraft Company, the plane was designed to probe the high speed relm of flight called the Sound Barrier, or Sonic Wall. At those speeds, approaching 760 miles per hour in the lower air, objects move faster than sound.Greater speeds in controlled airplanes would mean better performance, and whole new generations of planes that could fly faster and farther than any then in existance. The NACA turned the fleet of XS-1 planes over to the newly created U.S. Air Force, established from the Army Air Corps. Yeager was chosen to pilot the craft.
Why Yeager?
The eagle-eyed pilot had spent his youth working on West Virgina oil fields with his father. There he had developed skill in hydraulic and mechanical equipment, and maintaining them. These were just the skills that Air Force managers thought would be needed to fly the research craft. "They chose me, because I could fly an airplane-and had a maintenance background," Yeager would say later. His being a certified fighter pilot and air Ace from World War II didn't hurt his chances on being selected, either.
But on his early flight trials of the XS-1, now renamed X-1, Yeager found that as the plane approached MACH ONE it shook violently, veering wildly. It seemed that should the craft actually reach the speed of sound it would fly apart, destroying itself-and its pilot.
But Yeager thought otherwise.
One of his team, Air Force Captain Jack Ridley, had a PhD in physics as well as a maintenance bent. The two studied the data from Yeager's flights, and determined that the tail of the plane had a fault. By its design, a shock wave of compressed air was forming up on the tail, blocking its surfaces from a smooth flow of air. The X-1's tail had simply quit flying.
Quickly, Ridley and Yeager modified the tail surfaces and were ready to try again against the 'Sonic Wall'.
On Tuesday, October 14, 1947 a B-47 bomber carried Yeager's X-1 plane into the air above Edwards Air Base in southern California. At 9:27am the signal was given to drop the plane from the carrier. Once clear, Yeager fired up the X-1's four rocket chambers, and blasted straight up. Gradually, the plane increased speed. "As we approached MACH ONE, the little meter inside the cockpit went straight off," Yeager recalled. "But, shoot, it only went up to MACH ONE anyway. They didn't have much faith in us!". But as the plane crossed the threshhold of MACH ONE, something unexpected happened. Instead of increasing its wild gyrations, the X-1 settled down. The flight smoothed out. Yeager had no trouble controlling it as it slowed back down, and landed safely.
The X-1's "flying tail" had proven to be the missing link in the quest to exceed supersonic flight.
Future airplanes would routinely -and safely- cross that once magic sonic wall.
Such fights today were made possible by the country boy from West Virginia-and his flying tail.
