Flight Instructor for Rotorcraft Category Helicopter Rating › XII. Special Operations › Task B. Pinnacle Operations

HI.XII.B.R7

Risk management

Vortex ring state (VRS).

Study note

Get a short, cited explanation of this element written from the FAA handbooks: the core idea, the numbers that matter, common test traps, and a quick self-check.

From the FAA library

Pilot's Handbook of Aeronautical Knowledge p. 14-28
Chapter 14: Airport Operations › En Route › Vortex Avoidance Procedures
Vortex Avoidance Procedures The following procedures are in place to assist pilots in vortex avoidance in the given scenario. • Landing behind a larger aircraft on the same runway— stay at or above the larger aircraft’s approach flight path…
Helicopter Flying Handbook p. 10-5
Chapter 10: Advanced Flight Maneuvers › Steep Approach
considered a steep approach. [Figure 10-4] Caution must be exercised to avoid the parameters for vortex ring state (20–100 percent of available power applied, airspeed of less than 10 knots, and a rate of descent greater than ... feet per minute (fpm)). For additional information on vortex ring state (formerly referenced as settling-with-power), refer to Chapter 11, Helicopter Emergencies and Hazards. Figure 10-4. Steep approach to a hover…
Pilot's Handbook of Aeronautical Knowledge p. 14-27
Chapter 14: Airport Operations › Wake Turbulence › Terminal Area
Vortex Strength Terminal Area Wake turbulence has historically been thought of as only a function of aircraft weight, but recent research considers additional parameters, such as speed, aspects of the wing, wake decay rates, and aircraft resistance to wake, just ... name a few. The vortex characteristics of any aircraft will be changed with the extension of flaps or other wing configuration devices, as well as changing speed. However, as the basic factors are weight and speed, the vortex strength increases…
Pilot's Handbook of Aeronautical Knowledge p. 14-27
Chapter 14: Airport Operations › En Route › Vortex Behavior
Vortex Behavior Trailing vortices have certain behavioral characteristics that can help a pilot visualize the wake location and take avoidance precautions. Vortices are generated from the moment an aircraft leaves the ground (until it touches down), since trailing vortices ... byproduct of wing lift. [Figure 14-46] The vortex circulation is outward, upward, and around the wingtips when viewed from either ahead or behind the aircraft. Tests with large aircraft have shown that vortices remain spaced a bit less than…
Helicopter Flying Handbook p. 11-19
Chapter 11: Helicopter Emergencies and Hazards › System Malfunctions › Loss of Tail Rotor Effectiveness (LTE)
Figure 11-9. Main rotor disk vortex interference. 5. A slow forward airspeed, typically at speeds where translational lift and translational thrust are in the process of change and airflow around the tail rotor will vary in direction and speed ... tailwinds from 120° to 240° [Figure 11-10], such as left crosswinds, causing high pilot workload. c. Tail rotor vortex ring state (210° to 330°). [Figure 11-11] Winds within this region will result in the development of the vortex…
Pilot's Handbook of Aeronautical Knowledge p. 14-26
Chapter 14: Airport Operations › Wake Turbulence
components and equipment if encountered at close range. For this reason, a pilot must envision the location of the vortex wake and adjust the flight path accordingly. Vortex Generation Lift is generated by the creation of a pressure differential over ... counter rotating cylindrical vortices. Most of the energy lies within a few feet of the center of each vortex. [Figure 14-45] Figure 14-45. Vortex generation…