Editing Area rule (section)

{{Short description|Aerodynamic concept}}
[[Image:Area rule unifilar drawing.svg|thumb|Cross-sectional area distribution along the complete airframe determines wave drag, largely independent of the actual shape. The blue and light green shapes are roughly equal in area.]]

The '''Whitcomb area rule''', named after [[NACA]] engineer [[Richard T. Whitcomb|Richard Whitcomb]] and also called the '''transonic area rule''', is a design procedure used to reduce an [[aircraft]]'s [[drag (physics)|drag]] at [[transonic]] speeds which occur between about [[Mach number|Mach]] 0.75 and 1.2. For supersonic speeds a different procedure called the '''supersonic area rule''', developed by NACA aerodynamicist [[Robert Thomas Jones (engineer)|Robert Jones]], is used.

Transonic is one of the most important speed ranges for commercial and military [[fixed-wing aircraft]] today, with transonic acceleration an important performance requirement for combat aircraft and which is improved by reductions in transonic drag.