Strake (aeronautics)

In aviation, a strake is an aerodynamic surface generally mounted on the fuselage of an aircraft to improve the flight characteristics either by controlling the airflow (acting as large vortex generators) or by simple stabilising effect.

In general a strake is longer than it is wide, in contrast to a winglet or a moustache.

Leading edge root extensions (LERX) are also sometimes referred to as wing strakes.

On both supersonic and subsonic types, smaller strakes are sometimes applied to the forward fuselage to control the fuselage flow at high angles of attack ; for example the Concorde SST has small nose strakes "to get a better directional stability".

For wing strakes, see Leading edge root extension (LERX).

Double delta wing aircraft (Concorde, Tupolev Tu-144, Boeing 2707 SST project) featured a forward extended leading edge that may be considered as a wing strake ; it provides the same additional vortex lift at high angle of attack by leading edge suction.

One or two ventral strakes are sometimes positioned under the fuselage, as large vortex generators, to provide a better tail surfaces efficiency. Typical examples can be seen on the SOCATA TB family or the Lockheed F-104 Starfighter.

One or two large fins or strakes are sometimes positioned under the rear fuselage or below the empennage, to provide adequate stability at high angles of attack when the tail fin is shielded from the main airstream by the fuselage and/or the wing wake. Typical examples can be seen on the Piaggio P.180 Avanti, Learjet 60 and Beechcraft 1900D.

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