FH.XI.G.K1

From the FAA library

• Helicopter Flying Handbookp. 11-11
  Chapter 11: Helicopter Emergencies and Hazards › Dynamic Rollover

  Dynamic Rollover A helicopter is susceptible to a lateral rolling tendency, called dynamic rollover, when it is in contact with the surface during takeoffs or landings. For dynamic rollover to occur, some factor must first cause the helicopter to roll ... pivot around a skid or landing gear wheel, until its critical rollover angle is reached. The angle at which dynamic rollover occurs will vary based on helicopter type. Then, beyond this point, main rotor thrust continues the roll and recovery…

• Helicopter Flying Handbookp. 11-12
  Chapter 11: Helicopter Emergencies and Hazards › Dynamic Rollover › Critical Conditions

  Critical Conditions Certain conditions reduce the critical rollover angle, thus increasing the possibility for dynamic rollover and reducing the chance for recovery. The rate of rolling motion is also a consideration because, as the roll rate increases, there ... reduction of the critical rollover angle at which recovery is still possible. Other critical conditions include operating at high gross weights with thrust (lift) approximately equal to the weight. Refer to Figure 11-5. The following conditions are most critical…

• Helicopter Flying Handbookp. 2-10
  Chapter 2: Aerodynamics of Flight › Airflow and Reactions in the Rotor Disk › Resultant Relative Wind

  highest. As blade speed decreases nearer the center of the disk, downward velocity is less. Figure 2-19. Rotational relative wind. Resultant Relative Wind The resultant relative wind at a hover is rotational relative wind modified by induced flow. This ... inclined downward at some angle and opposite the effective flightpath of the airfoil, rather than the physical flightpath (rotational relative wind). The resultant relative wind also serves as the reference plane for development of lift, drag, and total aerodynamic force…

• Helicopter Flying Handbookp. 2-9
  Chapter 2: Aerodynamics of Flight › Airflow and Reactions in the Rotor Disk › Rotational Relative Wind (Tip-Path Plane)

  Airflow and Reactions in the Rotor Disk Relative Wind Knowledge of relative wind is essential for an understanding of aerodynamics and its practical flight application for the pilot. Relative wind is airflow relative to an airfoil. Movement of an airfoil ... through the air creates relative wind. Relative wind moves in a direction parallel to but opposite of the movement of the airfoil. [Figure 2-15] There are two parts to wind passing a rotor blade: • Horizontal part—caused…

• Helicopter Flying Handbookp. 11-13
  Chapter 11: Helicopter Emergencies and Hazards › Dynamic Rollover › Precautions

  When the upslope skid or wheel hits the ground, the dynamics of the motion can cause the helicopter to bounce off the upslope skid or wheel, and the inertia can cause the helicopter to roll about the downslope ground contact ... skid or wheel on the ground, the helicopter can roll over on its side. Precautions To help avoid dynamic rollover: 1. Always practice hovering autorotations into the wind, and be wary when the wind is gusty or greater than…

• Aviation Maintenance Technician Handbook - Generalp. 5-40
  Chapter 5: Physics for Aviation › Dynamic Stability

  Dynamic Stability The dynamic stability of an airplane involves the amount of time it takes for it to react to its static stability after it has been displaced from a condition of equilibrium. Dynamic stability involves the oscillations that typically ... return to its original position or attitude. Even though an airplane may have positive static stability, it may have dynamic stability which is positive, neutral, or negative. Imagine that an airplane in straight-and-level flight is disturbed and pitches…