Incidence, Sideslip, & Airspeed

For fixed-wing aircraft, the angle, α, computed by the Incidence, Sideslip, & Airspeed block is the angle between the relative wind and the longitudinal axis of the airframe. This angle is denoted in many aerospace engineering references as angle of attack. Incidence, Sideslip, & Airspeed refers to this angle as the incidence angle.

In the case of vertical takeoff and landing (VTOL) configurations, the equations used for computation are the same as that for fixed-wing aircraft [1]. However, in maneuvers involving transitions between cruise and hover, there are likely scenarios involving low or zero values of velocity resulting in incorrect incidence and side-slip angles. Therefore, the use of this block for analysis of VTOL configurations is not recommended. As an alternative, use the 6DOF Wind (Quaternion) or 6DOF Wind (Wind Angles) blocks, which provide α and β as outputs.