What occurs when a helicopter hovers out of ground effect?

When a helicopter hovers out of ground effect, one key phenomenon is the increased induced flow and the formation of a full vortex. In ground effect, the helicopter experiences a reduction in induced drag and an increase in lift due to the interaction of the rotor downwash with the ground. When the helicopter hovers out of ground effect, the rotor system cannot effectively leverage this interaction, resulting in increased induced flow which can lead to a full vortex ring state.

In this situation, the rotor blades work harder to maintain lift, and the flow of air is less efficient compared to hovering within ground effect. This can lead to increased power demands and a higher vulnerability to disturbances, making it more challenging to maintain a stable hover.

Understanding this concept is critical for pilots, as hovering out of ground effect requires more power and can result in decreased performance if not managed properly. The dynamics involved in this scenario highlight the importance of ground effect for maintaining lift and stability in hover operations, reinforcing why the initial choice regarding increased induced flow and vortex generation is accurate.