Depending on the context, “stabilizer” may sometimes describe only the tailless aircraft in theory and practice pdf part of the overall surface. Since obtaining static stability often requires that the aircraft center of gravity be ahead of the center of lift of a conventional wing, a stabilizer positioned aft of the wing is then often required to produce negative lift.
This is the most common configuration. Lacking elevators, the tailplanes of these aircraft were not what is now called conventional stabilizers. In naturally unstable aircraft, the canard surfaces may be used as an active part of the artificial stability system, and are sometimes named horizontal stabilizers. Tailless aircraft lack a separate horizontal stabilizer.
In a tailless aircraft, the horizontal stabilizing surface is part of the main wing. Less commonly, there is no hinge and the whole fin surface is pivoted for both stability and control. When an aircraft encounters a horizontal gust of wind, yaw stability causes the aircraft to turn into the wind, rather than turn in the same direction. Fuselage geometry, engine nacelles and rotating propellers all influence lateral static stability and affect the required size of the stabilizer.
Although the use of a vertical stabilizer is most common, it is possible to obtain directional stability with no discrete vertical stabilizer. One approach is to use differential drag. By increasing drag on the outer wing and reducing drag on the inner wing, a corrective moment can be applied to restore the aircraft attitude and correct the yaw. When the aircraft is rotated in yaw the outer wing sweep is reduced, so increasing drag, while the inner wing sweep increases, reducing drag. This change in the drag distribution creates a restoring moment. Another approach is to use differential air braking to affect the drag directly. The V-tail thus acts both as a yaw and pitch stabilizer.
This often results in an upsizing in the total area that reduces or negates the original benefit. V-tail with surfaces that extended through the fuselage to the opposite side. Horizontal tail” or “tail” terms are generally used in lieu of “stabilizer”. 1 Fundamentals of Static Equilibrium and Stability”. 2 Pitch Stability of a Cambered Wing”.