NASA Dryden Flight Research Center Collection

F-8 DFBW pilot-induced oscillations

This 28 second movie clip shows pilot induced oscillations on the F-8 DFBW aircraft.

From 1972 to 1985 the NASA Dryden Flight Research Center conducted flight research with an F-8C employing the first digital fly-by-wire flight control system without a mechanical back up. The decision to replace all mechanical control linkages to rudder, ailerons, and other flight control surfaces was made for two reasons. First, it forced the research engineers to focus on the technology and issues that were truly critical for a production fly-by-wire aircraft. Secondly, it would give industry the confidence it needed to apply the technology--confiden ce it would not have had if the experimental system relied on a mechanical back up.

In the first few decades of flight, pilots had controlled aircraft through direct force--moving control sticks and rudder pedals linked to cables and pushrods that pivoted control surfaces on the wings and tails.

As engine power and speeds increased, more force was needed and hydraulically boosted controls emerged. Soon, all high-performance and large aircraft had hydraulic-mechanical flight-control systems. These conventional flight control systems restricted designers in the configuration and design of aircraft because of the need for flight stability.

As the electronic era grew in the 1960s, so did the idea of aircraft with electronic flight-control systems. Wires replacing mechanical devices would give designers greater flexibility in configuration and in the size and placement of components such as tail surfaces and wings. A fly-by-wire system also would be smaller, more reliable, and in military aircraft, much less vulnerable to battle damage. A fly-by-wire aircraft would also be much more responsive to pilot control inputs. The result would be more efficient, safer aircraft with improved performance and design.

F-8 DFBW Project Home Page [ http://www.nasa.gov…]

April 18, 1978

Still photos [ http://www.dfrc.nas…] of this aircraft are available in several resolutions.

Langley Research Center

Dryden Flight Research Center

NASA

Enterprise

Neil Armstrong

John Manke

F/A-18

F-8

Digital Fly-By-Wire

flight control

Apollo

Gary Krier

F-16

space shuttles

pilot induced oscillation

Boeing 777

Neil A. Armstrong

WIRE

Dryden Flight Research Center (DFRC)

Langley Research Center (LaRC)

April 18, 1978

1978

EM-0044-01

SPD-DRYDEN-EM-0044-0 1

http://www.dfrc.nas…