Trailing edge

For trailing edge in electronics, the back edge of a digital signal, see Signal edge.
Cross section of an aerodynamic surface with the trailing edge emphasised
An American Aviation AA-1 Yankee being refuelled. Its wing trailing edge can be seen with aileron (deployed downwards) and flap.

The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.[1] Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft.[2] Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft.

The shape of the trailing edge is of prime importance in the aerodynamic function of any aerodynamic surface. A sharp trailing edge is always employed in an airfoil.[3] George Batchelor has written about:

“ ... the remarkable controlling influence exerted by the sharp trailing edge of an aerofoil on the circulation.”[4]
  1. ^ Crane, Dale: Dictionary of Aeronautical Terms, third edition, page 521. Aviation Supplies & Academics, 1997. ISBN 1-56027-287-2
  2. ^ Wragg, David W. (1973). A Dictionary of Aviation (first ed.). Osprey. p. 262. ISBN 9780850451634.
  3. ^ “It has been known from the very beginning of flight that wings with a sharp trailing edge must be used in order to obtain a well-defined lift.” von Mises, Richard (1945), Theory of Flight, Section VIII.2, p.179, Dover Publications Inc. ISBN 0-486-60541-8
  4. ^ Batchelor, G. K. (1967), An Introduction to Fluid Dynamics, p.438, Cambridge University Press.