The Whitcomb area rule, named after NACA engineer Richard Whitcomb and also called the transonic area rule, is a design procedure used to reduce an aircraft's drag at transonic speeds which occur between about Mach 0.75 and 1.2. For supersonic speeds a different procedure called the supersonic area rule, developed by NACA aerodynamicist Robert Jones, is used.
April 1955: Whitcomb examines a model aircraft designed in accordance with his area rule.
The F-106 Delta Dart, a development of the F-102 Delta Dagger, shows the "wasp-waisted" shaping due to area rule considerations
NASA Convair 990 with antishock bodies on the rear of the wings
Northrop F-5 showing fuselage waisting
National Advisory Committee for Aeronautics
The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets and personnel were transferred to the newly created National Aeronautics and Space Administration (NASA). NACA is an initialism, i.e., pronounced as individual letters, rather than as a whole word.
The inscription on the wall is NACA's mission statement: "...It shall be the duty of the advisory committee for aeronautics to supervise and direct the scientific study of the problems of flight with a view to their practical solution ..." By an Act of Congress Approved March 3, 1915
The first meeting of the NACA in 1915
The NACA Test Force at the High-Speed Flight Station in Edwards, California. The white aircraft in the foreground is a Douglas Skyrocket.
An engineer makes final calibrations to a model mounted in the 6-by-6-foot (1.8 m × 1.8 m) supersonic wind tunnel.