# alphabeta

Compute incidence and sideslip angles

## Description

`[`

computes `incidence`

`sideslip`

]
= alphabeta(`velocities`

)*m*
incidence and sideslip angles, `incidence`

and
`sideslip`

, between the velocity vector,
`velocities`

, and the body.

**Note**

For fixed-wing aircraft, the angle, α, computed by the alphabeta function 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.

`alphabeta`

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 function for analysis of VTOL configurations is not recommended.

## Examples

## Input Arguments

## Output Arguments

## References

[1] C. Venkatesan, *Fundamentals of Helicopter Dynamics*: CRC Press, 261. Boca Raton, FL 2015.

## Version History

**Introduced in R2006b**