NASA Aeronautics Research Goes Digital


During the latter 1960s and into the 1970s NASA pursued digital computational capabilities and achieved several significant results. One of the great successes in this arena has been the development of Digital Fly-By-Wire (DFBW) technology. The DFBW program originated at NASA’s Flight Research Center—now Armstrong Flight Research Center (AFRC)—in the late 1960s as a means of replacing conventional hydraulic and mechanical flight controls on an aircraft with an electronic control system. Flight controls, rather than being directly  linked to the control surfaces of the flight vehicle were converted to electronic signals transmitted by electrical wires—therefore fly-by-wire—between the pilot and the exterior of the plane. In such a system, computers took over much more of the control functions of the aircraft, and could through automatic signals fully control the vehicle.

F-8 Digital Fly-by-Wire (DFBW) aircraft in flight over snow capped mountains. Externally identical to a standard Navy F-8C, this aircraft had its control system replaced initially by a primary system using an Apollo digital computer. The backup system used three analog computers. When the pilot moved the airplane's stick and rudder, electronic signals went to the computer, which would generate signals to move the control surfaces. The system was designed so that the digital fly-by-wire aircraft would handle almost identically to a standard F-8C. Later, in Phase 2, the aircraft used three IBM AP-101 computers for its flight control system.

F-8 Digital Fly-by-Wire (DFBW) aircraft in flight over snow capped mountains. Externally identical to a standard Navy F-8C, this aircraft had its control system replaced initially by a primary system using an Apollo digital computer. The backup system used three analog computers. When the pilot moved the airplane’s stick and rudder, electronic signals went to the computer, which would generate signals to move the control surfaces. The system was designed so that the digital fly-by-wire aircraft would handle almost identically to a standard F-8C. Later, in Phase 2, the aircraft used three IBM AP-101 computers for its flight control system. (NASA Photo ECN-3478)

The NASA Flight Research Center led this effort, building on pioneering efforts in fly-by-wire control developed for the lifting body program and the Lunar Landing Research Vehicle of the 1960s. Such NASA engineers as Melvin Burke, Calvin Jarvis, Dwain Deets, and Kenneth Szalai, taking a suggestion from Neil Armstrong who had experience with those earlier efforts, modified an F-8 fighter aircraft to test DBFW conceptions beginning in 1976 and continuing for 9 years. A total of 211 flights on the F-8 were flown. Through this and other research efforts the insertion of computer technology into the flight control systems became the norm. Electrical flight controls thereafter replaced large bundles of mechanical and hydraulic connections on all aircraft everywhere in the world.

As a second example NASA worked during the 1970s and 1980s to develop the most efficient aircraft engine imaginable, the advanced turboprop. This program originated in 1976 at NASA’s Lewis Research Center (now Glenn Research Center) as a means of addressing the need to reduce fuel consumption costs during the height of the energy crisis of the period. NASA undertook six separate projects to improve aircraft fuel efficiency some of them relatively simple and others more complex. The Advanced Turboprop Project promised the greatest payoff, but was also the most technically demanding.

The energy crisis in the early 1970s served as the impetus for a generation of fuel-efficient mechanisms, especially in the field of aeronautics. NASA answered this call by initiating several research programs, one of which was the Advanced Turboprop Project at the then-Lewis Research Center.

The energy crisis in the early 1970s served as the impetus for a generation of fuel-efficient mechanisms, especially in the field of aeronautics. NASA answered this call by initiating several research programs, one of which was the Advanced Turboprop Project at the then-Lewis Research Center. (NASA Photo)

NASA engineer Daniel Mikkelson, working with others, pursued swept propeller blades to reduce noise and increase efficiency, generating a patent. Other aspect of this research led to better fuel management using computing technologies. Collectively, the advanced turboprop project received the Robert J. Collier Trophy for outstanding achievement in aerospace for 1987. While the energy crisis had abated by the time that the program was terminated, some of the knowledge gained from this effort have found their way into later aircraft designs.

Finally, NASA researchers also worked to perfect the so-called “Glass Cockpit” in the 1980s and 1990s. Replacing the longstanding mechanical instruments of the flight deck, the “glass cockpit” featured digital displays of LCD screens to communicate the standard information—altitude, rates of climb or descent, power settings, airspeed, and the like—as an integrated flight management system. The technology greatly simplified aircraft operation and navigation and allowed pilots greater flexibility and ease of understanding about what was taking place on the aircraft. They eliminated complexity, increased efficiency, and reduced costs. Every large aircraft built since the 1980s has employed this technology and increasingly smaller aircraft include it as well.

NASA 737 Glass Cockpit

The aft flight deck of the NASA 737 in 1987. An upgrade in 1986 replaced four original 5×7 monochrome displays with eight 8×8 color monitors. (NASA Photo L-87-03645)

NASA’s role in the development of this technology took several forms. First, researchers sought to reduce the number of instruments on a flight deck—some larger aircraft had more than 100—and digital technologies on a screen allowed the multi-tasking of individual components. NASA’s research on displays led to the creation of an integrated, easily mastered flight profile, what has come to be known as aircraft “situational awareness.” NASA then used a Boeing 737 test bed at the Langley Research Center to undertake a series of flights to prove the concept. It was successful beyond all expectations, although it took some time to convince aircraft manufacturers to adopt it because of the costs of transition. Since before 2000, however, all have acknowledged the great benefits of this new technology and it is now ubiquitous in the industry.

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3 Responses to NASA Aeronautics Research Goes Digital

  1. Jack Fisher says:

    NASA’s fly-by-wire project was documented in James E. Tomayko’s book Computers Take Flight, A History of the NASA’s Pioneering Digital Fly-by Wire Project. NASA History Series, 2000,

    Like

  2. damara137 says:

    It would be wonderful if you could include a PDF file with your blog posts. I’d love to print a compilation of them for my library!

    Like

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