Narrow Waist

Computer rendering of two jets with different waist designs.
Some high-speed airplanes, like the F-5, have a fuselage (body) that narrows in the middle to help reduce drag at high speeds.
Credit: National Air and Space Museum, Smithsonian Institution

Imagine slicing up this airplane like a loaf of bread. Where the wings add to the cross section, the fuselage narrows to compensate. This creates a more gradual change in total cross-sectional area than if the fuselage was uniformly thick. The result: weaker shock waves and less drag than if there were abrupt changes in the cross section.