HI.X.A.R3

From the FAA library

• Helicopter Flying Handbookp. 11-9
  Chapter 11: Helicopter Emergencies and Hazards › Vortex Ring State

  helicopter begins to descend vertically, it settles into its own downwash, which greatly enlarges the tip vortices. In this vortex ring state, most of the power developed by the engine is wasted in circulating the air in a doughnut pattern ... result, the airflow of the inner blade sections is upward relative to the disk. This produces a secondary vortex ring in addition to the normal tip vortices. The secondary vortex ring is generated about the point on the blade where…

• Helicopter Flying Handbookp. 11-20
  Chapter 11: Helicopter Emergencies and Hazards › System Malfunctions › Tail Rotor Vortex Ring State (210–330°)

  imperative to maintain positive control of the yaw rate and devote full attention to flying the helicopter. Tail Rotor Vortex Ring State (210–330°) Winds within this region cause a tail rotor vortex ring state to develop. [Figure ... result is a nonuniform, unsteady flow into the tail rotor. The vortex ring state causes tail rotor thrust variations, which result in yaw deviations. The net effect of the unsteady flow is an oscillation of tail rotor thrust. Rapid…

• Helicopter Flying Handbookp. 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 Knowledgep. 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…

• 14 CFR Part 47 — Aircraft RegistrationOpen
  14 CFR § 47.9 Corporations not U.S. citizens.

  certificate of incorporation; (2) A certification that it is lawfully qualified to do business in one or more States; (3) A certification that the aircraft will be based and primarily used in the United States; and (4) The location where ... will be maintained. (b) For the purposes of registration, an aircraft is based and primarily used in the United States if the flight hours accumulated within the United States amount to at least 60 percent of the total flight hours…