Forty Years: NASA's Aviation Safety Efforts Soar
ajor strides have
been made during the last 40 years to make flying the safest of all major
modes of transportation. The story of military aviation and the American
aircraft industry during World War II is well known. Lesser known, but
no less meaningful, is NASA's important contributions to aviation through
its research, development and production of military aircraft for use
during World War II. This beneficence serves as the foundation of NASA's
present aeronautical research, accomplishments, goals and partnerships.
More technological advances are needed, however, to prevent a rise in accidents if air traffic triples as predicted in the next 20 years. NASA is leading the nation's efforts with its aviation safety partnerships and its own ongoing endeavors to reduce general aviation accidents by 80 percent in 10 years—and by 90 percent in two decades.
NASA's Efforts Today
The most recent development toward this goal is NASA's Aviation Safety Program, an ambitious $500 million program in partnership with the Federal Aviation Administration (FAA), the aviation industry and the Department of Defense. The Aviation Safety Program emphasizes not only accident reduction, but also a decrease in injuries when accidents do occur. The program will include research to reduce human-error-caused accidents and incidents, predict and prevent mechanical and software malfunction and eliminate accidents involving hazardous weather and controlled flight into terrain.
Information technology will be used to build a safer aviation system to support pilots and air traffic controllers. The FAA will help define requirements and actions to enact many of the safety standards.
NASA's ongoing air safety efforts include the Advanced General Aviation Transport Experiments (AGATE), the General Aviation Propulsion (GAP) Program and the Advanced Aircraft Transportation Technologies (ATT) Program. Significant accomplishments by NASA and its partnerships with the FAA and private industry to make aviation safer include:
• Providing technology for advanced warning of wind shear
• Designing advanced air traffic management equipment and procedures
• Developing ways to ensure older aircraft are as structurally sound
as new ones
• Improving engine reliability systems and displays
• Developing advanced ice protection concepts to improve aircraft
operations
• Improving the control of general aviation aircraft stall and spin
NASA's Role in General Aviation History: The Untold Story
Much of what we take for granted in aviation today, and the recent past, was pioneered by the National Advisory Committee for Aeronautics (NACA), the group we know today as NASA under the National Aeronautics and Space Act of 1958. As the United States entered World War II on December 8, 1941, the NACA increased in size from one research facility—the Langley Memorial Aeronautical Laboratory in Hampton, Virginia—to three. Ames Aeronautical Laboratory in Mountain View, California, and the Aircraft Engine Research Laboratory in Cleveland, Ohio (Lewis Research Center today), were brand new. Those three facilities and Dryden Flight Research Center in Edwards, California, continue to be among the leaders in NASA's aviation research today.
The NACA's fundamental research agenda (basic research, mainly aerodynamics and flight research) proved a solid foundation for its new wartime responsibilities. The NACA mandate to find "practical solutions" assumed paramount importance in guiding the organization during the war. The NACA had a new role in conducting applied development work for industry and the military. Among the many important accomplishments during the war, a few of the NACA's major research projects included drag cleanup, de-icing, engine development, low-drag wing, stability and control, compressibility, ditching and seaplane studies.
"Drag cleanup" (minimizing airflow resistance) was the most important work for the NACA during the war, using what was the largest facility in the world at the time—a full-scale, 40- by 80-foot wind tunnel. The "drag cleanup" process helped the military solve technical problems, and it was quick and inexpensive. Time-consuming and expensive aircraft redesign became unnecessary.
Right from the start, the entire aviation community was unanimous in its desire to develop a system that would make flying safer. When ice covers wings and propellers, reducing lift and increasing drag, the result can often be fatal crashes. Icing studies were started at Langley. Work was transferred to Ames and consisted of both research and extensive design of actual hardware used on airplanes. Significant research on icing today is done at Lewis Research Center. The NACA developed a heat de-icing system, which piped air heated by hot engine exhaust along the leading edge of the wing. The system saved the lives of countless pilots flying in dangerous weather conditions. The NACA was awarded the Collier Trophy, aviation's highest award, for its de-icing work.
The NACA pioneered new methods of "troubleshooting" defects in new, higher powered piston engines at the new Aircraft Engine Research Laboratory in Cleveland, beginning in 1942. Engineers closely examined engines slated for rapid production and use in military aircraft. They developed new ways to solve complex combustion, heat exchange and supercharger problems. They swiftly introduced a single standard test procedure and followed by developing the centrifugal supercharger—work that was extremely useful to manufacturers.
Engine research did not receive very much public attention then. Work performed at the laboratory on an army aircraft, however, went on to become one of the military's most successful—the Army's Boeing B-17 Flying Fortress, a true high-altitude, high-speed bomber.
The NACA researchers had been virtually excluded from some aspects of wartime jet propulsion research and were behind Great Britain and Germany in jet aircraft development. Nonetheless, the NACA engine research facility tested the General Electric I-16 turbojet engine, and a dedicated group at the engine laboratory seized every opportunity to work on the General Electric project, thus building the foundation for the NACA's postwar work on jet engine technology.
A new series of airfoils (a wing's cross-sectional shape), developed by the NACA, was the basis of the NACA's low-drag wing research, which had a profound effect on the outcome of World War II. Most enemy fighters were outclassed in aerial combat from the NACA's low-drag laminar flow airfoils that created high speed at cruise conditions.
Representing a decade of work, the NACA introduced to industry a new set of quantitative measures to characterize the stability, control and handling qualities of an airplane. The military readily adopted the NACA findings and spin tunnel tests. This work led to the military's first-ever issuance of specific design standards to its aircraft manufacturers and to changes in airplane tail design to help pilots recover from high-speed dives.
NACA research also produced vital information on airflow over wing surfaces and dive flaps that helped pilots retain control over a diving airplane. The NACA also was asked to assist in finding information to help air crews and aircraft better withstand water impacts. The NACA's test results were forwarded to aircraft manufacturers and helped save the lives of countless air crews.
NASA began full-scale research when it was the NACA. In its 40 years, four basic tools have been used: computational fluid dynamics, wind tunnels, ground-based flight simulators and flights of the vehicles themselves.
Until the 1970s, experimental planes (designated "X"-planes for "experimental") were the chief research tools. This was simply because research at Dryden probed flight regimes that wind tunnels, simulators and production aircraft could not approach, until the breaking of the "sound barrier" by the XS-1 brought proof that the best available supersonic wind tunnel data were reliable. Vast amounts of data that the X-1s and other early research airplanes obtained were important for validating the new wind tunnels (particularly the ventilated-throat transonic tunnels) under development at the time. One of the greatest benefits was intangible—the confidence gained at the time by the achievement of safe, controllable supersonic flight.
The X-15s of the 1950s and 1960s helped verify theories and wind tunnel predictions concerning hypersonic flight (at speeds greater than Mach 5). The X-15 program data in more than 750 research papers and reports had real-life applications as well, such as the practical, full-pressure flight suit for pilot protection in space, the first large, restartable, throttleable rocket engine and the first reusable aircraft structure capable of withstanding the temperatures of hypersonic reentry into the atmosphere. The program also illuminated discoveries about hypersonic aerodynamic heating that were not predicted by other methods. Similar to the 1940s supersonic research, the X-15 program gathered unique data, and it expanded the human experience—this time successfully taking piloted flight to the edge of space.
The NASA F-8 Digital-Fly-by-Wire is an example of a conventional aircraft that became an important research vehicle. It was a former Navy fighter, modified in the early 1970s so it could be flown with computer-driven, electronic flight controls instead of the mechanical types that were common on all aircraft at the time. It was the forerunner of the fly-by-wire flight control systems that are now the norm on space vehicles, the latest airliners and virtually all new fighter aircraft. Its use on the X-29 proved that even an extremely unstable aircraft could be flown with superior reliability.
In its efforts to ensure safer skies for commercial, military and private aircraft, NASA is seeing promising results.
For more information, contact Karen Kafton at the National Technology
Transfer Center.
(800) 678-6882, Fax: (304) 243-2457, E-mail: kkafton@nttc.edu.
Please mention you read about it in Innovation.
The historical wind tunnel at Langley Research Center, famous for pioneering drag research, was still used in the 1970s.
Ground was broken in the early 1940s for an aircraft engine research lab at Lewis Research Center.
The 40- by 80-foot wind tunnel under construction at Ames Research Center
in 1943—at the time the world's largest.
