Editing Delta wing (section)

====Transonic and low-supersonic flight====
[[File:194th Fighter-Interceptor Squadron - Convair F-106A-135-CO Delta Dart 59-0136.jpg|thumb|Convair made several supersonic deltas. This is an [[Convair F-106 Delta Dart|F-106 Delta Dart]], a development of their earlier F-102 Delta Dagger]]
With a large enough angle of rearward sweep, in the [[transonic]] to low [[supersonic]] speed range the wing's leading edge remains behind the [[shock wave]] boundary or [[shock cone]] created by the leading edge root.

This allows air below the leading edge to flow out, up and around it, then back inwards creating a sideways flow pattern similar to subsonic flow. The lift distribution and other aerodynamic characteristics are strongly influenced by this sideways flow.<ref name="mason10-1">Mason, Chap. 10, pp. 9–12.</ref>

The rearward sweep angle lowers the airspeed normal to the leading edge of the wing, thereby allowing the aircraft to fly at high [[subsonic flight|subsonic]], transonic, or supersonic speed, while the subsonic lifting characteristics of the airflow over the wing are maintained.

Within this flight regime, drooping the leading edge within the shock cone increases lift, but not drag to any significant extent.<ref>Boyd, Migotzky and Wetzel; "A Study of Conical Camber for Triangular and Sweptback Wings", Research Memorandum A55G19, NACA, 1955.[http://nix.nasa.gov/search.jsp?R=19930090334&qs=N%3D17%2B4293246867]{{dead link|date=June 2021|bot=medic}}{{cbignore|bot=medic}}</ref> Such conical leading edge droop was introduced on the production [[Convair F-102A Delta Dagger]] at the same time that the prototype design was reworked to include [[Area rule|area-ruling]]. It also appeared on Convair's next two deltas, the [[F-106 Delta Dart]] and [[B-58 Hustler]].<ref>Mason, Chap. 10, p. 16.</ref>