Kawalki's airfoil shapes were identical to those subsequently produced by the American aerodynamicist RichardвЂ…Whitcomb. Testing of these airfoils was reported by B. Kawalki at DeutscheвЂ…VersuchsanstaltвЂ…fГјrвЂ…Luftfahrt Berlin-Adlershof designed a number of airfoils characterised by elliptical leading edges, maximal thickness located downstream up to 50% chord and a flat upper surface. The supercritical airfoil was first suggested by aerodynamicists in Germany during the SecondвЂ…WorldвЂ…War. Accordingly, techniques learned from studies of the original supercritical airfoil sections have been used to design airfoils for several high-speed subsonic and transonic aircraft, from the AirbusвЂ…A310 and BoeingвЂ…777 airliners to the McDonnellвЂ…DouglasвЂ…AV-8BвЂ…HarrierвЂ…II jumpjet. In America, the aerodynamicist RichardвЂ…Whitcomb produced supercritical airfoils identical to Kawalki's earlier work these were used to devise a supercritical wing that was, in turn, incorporated into both civil and military aircraft. In particular, HawkerвЂ…SiddeleyвЂ…Aviation designed a number of advanced airfoils that were, amongst other programmes, incorporated into the AirbusвЂ…A300. Following the end of the conflict, multiple nations continued research into the field, including Germany, the UnitedвЂ…Kingdom, and the UnitedвЂ…States. Kawalki, who designed a number of airfoils during the SecondвЂ…WorldвЂ…War. The origins of the supercritical airfoil can be traced back to the German aerodynamicist K.В A. Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing. The formation of these shockwaves causes wave drag. As the speed of the aircraft approaches the speedвЂ…ofвЂ…sound, the air accelerating around the wing reaches Mach 1 and shockwaves begin to form.

Both the thickness distribution and the camber of the wing determine how much the air accelerates around the wing. Standard wing shapes are designed to create lower pressure over the top of the wing. Supercritical airfoils are characterized by their flattened upper surface, highly cambered ('downward-curved') aft section, and larger leading-edge radius compared with NACAвЂ…6-series laminar airfoil shapes. Since the airfoil shape allows efficient flight at supercritical flight speeds, a wing of such design is called a supercritical wing.A supercritical airfoil ( supercritical aerofoil in British English) is an airfoil designed primarily to delay the onset of waveвЂ…drag in the transonic speed range. Supercritical airfoils are shaped to substantially reduce the strength of the shock wave and to delay the associated boundary-layer separation (illustration b). See Aerodynamic force, Aerodynamic wave drag, Transonic flight The severe turbulence also caused buffet or shaking of the aircraft and substantially changed its stability or flying qualities. The increased turbulence leads to a severe increase in drag and loss in lift, with a resulting decrease in flight efficiency. This local wave caused an abrupt increase in the pressure on the surface of the wing, which may cause the surface boundary-layer flow to separate from the surface, with a resulting severe increase in the turbulence of the flow. On previous aircraft, this supercritical flow resulted in the onset of a strong local shock wave above the upper surface of the wing (illustration a). Such a condition is called supercritical flow. When the speed of an aircraft approaches the speed of sound, the local airflow about the airplane, particularly above the upper surface of the wing, may exceed the speed of sound. Supercritical wingДЄ wing with special streamwise sections, or airfoils, which provide substantial delays in the onset of the adverse aerodynamic effects which usually occur at high subsonic flight speeds. McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright В© 2003 by The McGraw-Hill Companies, Inc.