HI.VII.C.K7

From the FAA library

• Helicopter Flying Handbookp. 2-19
  Chapter 2: Aerodynamics of Flight › Forward Flight › Airflow in Forward Flight

  blade continues to rotate, velocity of the airflow then increases to rotational velocity over the tail. It continues to increase until the blade is back at the 3 o’clock position. The advancing blade in Figure 2-35, position ... moves in the same direction as the helicopter. The velocity of the air meeting this blade equals rotational velocity of the blade plus wind velocity resulting from forward airspeed. The retreating blade (position C) moves in a flow…

• Aeronautical Information Manualp. 7-1-43
  Chapter 7. Safety of Flight › Section 1. Meteorology › 7-1-14. Reporting of Cloud Heights

  meter increments for products between 1,200 meters and 2,000 meters. 7-1-14. Reporting of Cloud Heights a. Ceiling, by definition in the CFRs and as used in aviation weather reports and forecasts, is the height above ground ... phenomenon that is reported as “broken,” “overcast,” or “obscuration,” e.g., an aerodrome forecast (TAF) which reads “BKN030” refers to height above ground level. An area forecast which reads “BKN030” indicates that the height is above mean sea level. b. Pilots…

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

  Figure 2-17. Induced flow. Figure 2-18. Normal induced flow velocities along the blade span during hovering flight. Downward velocity is highest at the blade tip where blade speed is highest. As blade speed decreases nearer the center ... 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 is inclined downward at some angle and opposite the effective…

• Helicopter Flying Handbookp. 2-19
  Chapter 2: Aerodynamics of Flight › Forward Flight › Dissymmetry of Lift

  retreating blade decreases, the blade loses lift and begins to flap down. It reaches its maximum downflap velocity at the 9 o’clock position, where wind velocity is the least. This downflap creates an upward flow ... same effect as decreasing the induced flow velocity by imposing an upward velocity vertical vector to the relative wind which increases the AOA. Figure 2-35. Airflow in forward flight. Dissymmetry of Lift Dissymmetry of lift is the differential (unequal…

• Helicopter Flying Handbookp. 2-8
  Chapter 2: Aerodynamics of Flight › Airfoil › Airfoil Terminology and Definitions

  important properties of an airfoil section. • Leading edge—the front edge of an airfoil. [Figure 2-12] • Flightpath velocity—the speed and direction of the airfoil passing through the air. For airfoils on an airplane, the flightpath velocity is equal ... true airspeed (TAS). For helicopter rotor blades, flightpath velocity is equal to rotational velocity, plus or minus a component of directional airspeed. The rotational velocity of the rotor blade is lowest closer to the hub and increases outward towards…

• Aviation Maintenance Technician Handbook - Generalp. 5-37
  Chapter 5: Physics for Aviation › Aircraft Theory of Flight › Bernoulli’s Principle and Subsonic Flow

  Daniel Bernoulli, a Swiss physicist. Bernoulli’s principle, as we refer to it today, states that “as the velocity of a fluid increases, the static pressure of that fluid will decrease, provided there is no energy added or energy taken ... exit. Figure 5-54 shows a converging shaped duct, with the air entering on the left at subsonic velocity and exiting on the right. Notice that the air exits at an increased velocity and a decreased static pressure when looking…