Editing Stall (fluid dynamics) (section)

===Tip stall===
Wing sweep and taper cause stalling at the [[wing tip|tip of a wing]] before the root. The position of a swept wing along the fuselage has to be such that the lift from the wing root, well forward of the aircraft center of gravity (c.g.), must be balanced by the wing tip, well aft of the c.g.<ref>{{Cite web |url=https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%200018.html |title=Archived copy |access-date=2019-03-06 |archive-date=2019-03-07 |archive-url=https://web.archive.org/web/20190307112308/https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%200018.html |url-status=dead }}</ref> If the tip stalls first the balance of the aircraft is upset causing dangerous nose [[pitch up]]. Swept wings have to incorporate features which prevent pitch-up caused by premature tip stall.

A swept wing has a higher lift coefficient on its outer panels than on the inner wing, causing them to reach their maximum lift capability first and to stall first. This is caused by the downwash pattern associated with swept/tapered wings.<ref>Fundamentals Of Flight – Second Edition, Richard S.Shevell, Prentice Hall 1983, {{ISBN|0-13-339060-8}}, p.244</ref> To delay tip stall the outboard wing is given [[Washout (aviation)|washout]] to reduce its angle of attack. The root can also be modified with a suitable leading-edge and airfoil section to make sure it stalls before the tip. However, when taken beyond stalling incidence the tips may still become fully stalled before the inner wing despite initial separation occurring inboard. This causes pitch-up after the stall and entry to a super-stall on those aircraft with super-stall characteristics.<ref>Handling The Big Jets – Third Edition, D.P.Davies, Civil Aviation Authority, p.121</ref> Span-wise flow of the boundary layer is also present on swept wings and causes tip stall. The amount of boundary layer air flowing outboard can be reduced by generating vortices with a leading-edge device such as a fence, notch, saw tooth or a set of vortex generators behind the leading edge.<ref>Flightwise – Principles Of Aircraft Flight, Chris Carpenter 1996, Airlife Publishing Ltd., {{ISBN|1 85310 719 0}}, p.369</ref>