Ever since man first took to the skies in powered aircraft, pilots and aviation engineers have sought to overcome challenges and push perceived boundaries as technology developed. One of the much debated challenges back in the early 1940s was whether it was possible for an aircraft to travel fast enough to break the sound barrier. On October 14, 1947, legendary pilot Chuck Yeager proved it was indeed possible when he pushed the Bell X-1 he was flying to Mach 1.06 (1,100 km/h; 700 mph) going down in history as the first pilot to break the sound barrier.
Nicknamed Glamorous Glennis in honor of Yeager’s wife, the Bell X-1 was built by the Bell Aircraft Company under the direction of a joint supersonic research project run by the National Advisory Committee for Aeronautics, the US Army Forces and the US Air Force. The concept for the airplane was developed in 1944 and it was built the following year. The fuselage of the X-1 was shaped like a 0.5-calibre machine gun bullet for stability and the thin wings were designed to reduce drag. As it was only later discovered that the swept-wing design is more efficient for speed, the X-1’s wings were at a 90 degree angle to the fuselage. The pilot was seated inside a confined cockpit in the nose, behind a sloped, framed window, and the airplane was powered by a single XLR-11 engine running on liquid oxygen, alcohol and water.
On the historic sound barrier breaking flight, the supersonic Bell X-1 was drop-launched from a B-29 Superfortress bomber airplane at an altitude of 23,000 feet (7,000 meters), where it quickly climbed to its test altitude of 43,000 feet (13,000 meters) and proceeded to break the sound barrier before landing on a dry lake bed. In recognition of their achievement, the 1948 Collier Trophy was awarded jointly to Larry Bell of Bell Aircraft, Captain Charles “Chuck” Yeager, and John Stack of the National Advisory Committee for Aeronautics.
As the first in the so-called X-planes, the X-1 set the pattern for future projects, with data collected during its test flights providing essential information for later aircraft designs.
Known primarily for his significant contributions to aviation technology, Leonard Michael Greene (1918-2006) was an American inventor who held over two-hundred patents. Many of Greene’s patents are related to aviation, with one of the most noteworthy being his Aircraft Stall Warning device which, as the name suggests, warns pilots of imminent aerodynamic stall. This is where the critical angle of attack, typically around 15 degrees, of the foil is exceeded resulting in a sudden reduction in lift. The warning device makes pilots aware that the airflow over the wings is not providing lift, allowing them to take the necessary action.
Greene’s invention was prompted by his witnessing an aircraft crash caused by stall when he was working as an aerodynamicist and engineering test pilot for Grumman Aircraft Corporation during World War II. At that time aerodynamic stalls were the cause of the majority of aviation accidents deaths and by the mid-1940s Greene had developed a way of warning the pilot timeously. His first warning device was powered by flashlight batteries, consisting of threaded bolts, a bicycle horn and an assortment of other components – rudimentary, but a step in the right direction. Greene filed to patent his device in 1944, with the patent being issued in 1949. In 1946, Greene founded the Safe Flight Instrument Corporation in White Plains, NY, where he developed, refined and marketed the aircraft stall warning device. The company went from strength to strength and has remained dedicated to the production of aviation safety and performance equipment for sixty years, with its principle products, many of which were invented by Greene,including FAA approved Stall Warning Systems, Angle-of-Attack Systems, Speed Control Systems, Speed Command of Attitude and Thrust (SCAT) systems, AutoPower, Airborne and Wind Shear Warning Systems and N1 Computer Systems.
Leonard Greene’s 2001 book Inventorship: The Art of Innovation details how he found creative inspiration in the simplest of things, with an example being his invention of a device to prevent the sonic boom caused by a supersonic aircraft when breaking the sound barrier by using a hollow fuselage and ducts to suck in, compress and release air through the aircraft’s tail – with his inspiration being the lowly earthworm’s method of moving through dirt by eating and excreting it.
Greene remained actively involved in Safe Flight Instrument Corporation until he passed away in 2006. His inventions and dedication to making flight safer has benefited millions of people who today view air travel as routine.
Chuck Yeager‘s most recognized achievement is being the first man to break the sound barrier, which he did on October 14, 1947 as a test pilot for the U.S. Air Force.
Much earlier in his career, Yeager flew for the U.S. Army Air Corps in World War II. Shortly after he claimed his first kill, he was shot down over enemy territory. The French resistance assisted him in his escape to Spain, and he subsequently returned to active duty. Before the war ended, Yeager had flown 64 combat missions with 13 enemy kills to his credit.
During the Korean War, Yeager set a new record by flying more than double the speed of sound with an airspeed of 1,650 mph. In addition to his duties as a test pilot in Korea, he also led a fighter squadron based in Europe.
Yeager was promoted to full colonel in time for the Vietnam War, during which he commanded the 405th fighter wing. In addition to also training bomber pilots, hew flew 127 air-support missions.
Yeager received a promotion to brigadier general in 1968, a rare achievement for someone who began his military career as an enlisted man. In 1976, he was awarded the Congressional Gold Medal. Some of his other numerous decorations include the Presidential Medal of Freedom, the Purple Heart, the Legion of Merit with oak leaf cluster, the Distinguished Flying Cross with two clusters, the Bronze Star with V device, the Silver Star with oak leaf cluster, the Air Medal with ten clusters, the Distinguished Service Medal, and the Air Force Commendation medal. In 1973, he became the first military pilot inducted into the Aviation Hall of Fame.
In 1979, Tom Wolfe immortalized Chuck Yeager in his best selling book, The Right Stuff which was later made into a movie.
One of the many reasons the concord was grounded was because of the massive amount of noise pollution generated as the aircraft continually broke the sound-barrier. But recent research and development efforts seem to be targeted towards getting supersonic aircraft back in the air on a commercial level. What has changed?
The Bangalore light combat aircraft (LCA) known as the Tejas not only enjoyed a successful maiden flight when it zipped through the skies over Bangalore on Monday evening, but it managed to become the second Tejas aircraft to break the sound barrier. The supersonic maiden test flight lasted approximately 43 minutes and saw the aircraft reach Mach 1.1 at an altitude of 9.5 km.
They may be well beyond the scope of the average businessman, but supersonic business jets are fast becoming hot property. With the ever-increasing demand for fast business jets, the market for small supersonic jets has exploded. Most of the major aircraft companies are gearing up for the demand by developing their own range of small super-fast jets and, despite massive price tags, it would seem consumers are lining up to purchase them.