Editing Area rule (section)

===Transonic area rule===
The area rule says that two airplanes with the same longitudinal cross-sectional area distribution have the same wave drag, independent of how the area is distributed laterally (i.e. in the fuselage or in the wing). Furthermore, to avoid the formation of strong shock waves the external shape of the aircraft has to be carefully arranged so that the cross-sectional area changes as smoothly as possible going from nose to tail. At the location of the wing, the fuselage is narrowed or "waisted". Fuselage cross-sectional area may need to be reduced by flattening the sides of the fuselage below a bubble canopy and at the tail surfaces to compensate for their presence, both of which were done on the [[Hawker Siddeley Buccaneer]].<ref>From Spitfire To Eurofighter 45 Years of Combat Aircraft Design, Roy Boot,{{ISBN|1 85310 093 5}}, p.93</ref>