Textron Inc.
System and Method for Protection Against Vortex Ring State

Abstract:

A system and method for protecting a rotorcraft from entering a vortex ring state, the method including monitoring a vertical speed of a rotorcraft, comparing the vertical speed to a vertical speed safety threshold, and performing vortex ring state (VRS) avoidance in response to the vertical speed exceeding the vertical speed safety threshold. The performing the VRS avoidance includes determining a power margin available from one or more engines of the rotorcraft, limiting the vertical speed of the rotorcraft in response to the power margin exceeding a threshold, and increasing a forward airspeed of the rotorcraft in response to the power margin not exceeding the threshold.