Energy–maneuverability theory is a model of aircraft performance. It was developed by
Col. John Boyd, a fighter pilot, and
Thomas P. Christie
Thomas Philip Christie (born May 28, 1934 in Pensacola, Florida) is an American defense analyst who worked for the U.S. government.
Christie graduated from Spring Hill College with a B.S. degree in mathematics in May 1955 and from New York Univer ...
, a mathematician with the
United States Air Force, and is useful in describing an aircraft's performance as the total of
kinetic
Kinetic (Ancient Greek: κίνησις “kinesis”, movement or to move) may refer to:
* Kinetic theory, describing a gas as particles in random motion
* Kinetic energy, the energy of an object that it possesses due to its motion
Art and ent ...
and
potential energies or
aircraft specific energy
Aircraft-specific energy is a form of specific energy applied to aircraft and missile trajectory analysis. It represents the combined kinetic and potential energy of the vehicle at any given time. It is the total energy of the vehicle (relative t ...
. It relates the
thrust,
weight,
aerodynamic drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
,
wing area, and other flight characteristics of an aircraft into a
quantitative model. This allows combat capabilities of various aircraft or prospective design
trade-offs to be predicted and compared.
Formula
All of these aspects of airplane performance are compressed into a single value by the following formula:
:
History
John Boyd, a U.S. jet fighter pilot in the
Korean War, began developing the theory in the early 1960s. He teamed with mathematician
Thomas Christie at
Eglin Air Force Base to use the base's high-speed computer to compare the
performance envelope
In aerodynamics, the flight envelope, service envelope, or performance envelope of an aircraft or spacecraft refers to the capabilities of a design in terms of airspeed and load factor or atmospheric density, often simplified to altitude. The t ...
s of
U.S.
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...
and
Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...
aircraft from the Korean and
Vietnam Wars. They completed a two-volume report on their studies in 1964. Energy Maneuverability came to be accepted within the U.S. Air Force and brought about improvements in the requirements for the
F-15 Eagle
The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather tactical fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force selected McDonnell Douglas's ...
and later the
F-16 Fighting Falcon
The General Dynamics F-16 Fighting Falcon is a single-engine multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful ...
fighters.
[Jenkins, Dennis R. ''McDonnell Douglas F-15 Eagle, Supreme Heavy-Weight Fighter'', p. 7. Aerofax, 1998.]
See also
*
Lagrangian mechanics
In physics, Lagrangian mechanics is a formulation of classical mechanics founded on the stationary-action principle (also known as the principle of least action). It was introduced by the Italian-French mathematician and astronomer Joseph-Lo ...
Notes
References
*Hammond, Grant T. ''The Mind of War: John Boyd and American Security''. Washington, D.C.: Smithsonian Institution Press, 2001. and .
*Coram, Robert. ''Boyd: The Fighter Pilot Who Changed the Art of War''. New York: Back Bay Books, 2002. and .
*
Wendl, M.J., G.G. Grose, J.L. Porter, and V.R. Pruitt
''Flight/Propulsion Control Integration Aspects of Energy Management'' Society of Automotive Engineers, 1974, p. 740480.
{{DEFAULTSORT:Energy-maneuverability theory
Aerospace engineering