Typically, the empennage consists of horizontal and vertical tails for aircraft stability and control. Various types of empennage configurations are described in Chapter 4. The dominant type has a vertical tail (V-tail; U. K. terms are fin and rudder) in the plane of symmetry with a symmetrical aerofoil. A horizontal tail (H-tail; U. K. terms are stabilizer and elevator) is like a small wing at the tail (i. e., the aft end of the fuselage). The last two decades have seen the return of aerodynamic surfaces placed in front of the wing (see Figure 3.48); these are called canards and are discussed in subsequent chapters. This section addresses the definitions associated with the empennage and canard as well as the tail volume coefficients (see Chapter 12).
The V-tail of a single-engine, propeller-driven aircraft may have an offset of 1 to 2 deg to counter the effects of rotating propeller slipstream.