CP.II.E.R5

From the FAA library

• Pilot's Handbook of Aeronautical Knowledgep. 5-7
  Chapter 5: Aerodynamics of Flight › Induced Drag

  vortices) roll off the back of your wing, they angle down, which is known as downwash. Figure 5-10 shows the difference in downwash at altitude versus near the ground. Bearing in mind the direction of rotation of these vortices ... seen that they induce an upward flow of air beyond the tip and a downwash flow behind the wing’s trailing edge. This induced downwash has nothing in common with the downwash that is necessary to produce lift…

• Pilot's Handbook of Aeronautical Knowledgep. 5-11
  Chapter 5: Aerodynamics of Flight › Ground Effect

  vertical component of the airflow around the wing is restricted by the surface. This alters the wing’s upwash, downwash, and wingtip vortices. [Figure 5-16] Ground effect, then, is due to the interference of the ground (or water) surface ... wing encounters ground effect and is maintained at a constant AOA, there is consequent reduction in the upwash, downwash, and wingtip vortices…

• Pilot's Handbook of Aeronautical Knowledgep. 5-16
  Chapter 5: Aerodynamics of Flight › Aircraft Design Characteristics › Longitudinal Stability (Pitching)

  balance. Even though the horizontal stabilizer may be level when the aircraft is in level flight, there is a downwash of air from the wings. This downwash strikes the top of the stabilizer and produces a downward pressure, which ... certain speed is just enough to balance the “lever.” The faster the aircraft is flying, the greater this downwash and the greater the downward force on the horizontal stabilizer (except T-tails). [Figure 5-24] In aircraft with fixed-position…

• Pilot's Handbook of Aeronautical Knowledgep. 5-47
  Chapter 5: Aerodynamics of Flight › Boundary Layer Separation › Shock Waves

  decrease in control force effectiveness. The loss of lift due to airflow separation results in a loss of downwash and a change in the position of the center pressure on the wing. Airflow separation produces a turbulent wake behind ... buffet (vibrate). The nose-up and nose-down pitch control provided by the horizontal tail is dependent on the downwash behind the wing. Thus, an increase in downwash decreases the horizontal tail’s pitch control effectiveness since it effectively increases…

• Aeronautical Information Manualp. 4-3-23
  Chapter 4. Air Traffic Control › Section 3. Airport Operations › 4-3-17. VFR Helicopter Operations at Controlled Airports

  pilot request. Preference should be given to this procedure whenever it is necessary to minimize effects of rotor downwash. 2. Pilots may request a hover taxi when slow forward movement is desired or when it may be appropriate to move ... very short distances. Pilots should avoid this procedure if rotor downwash is likely to cause damage to parked aircraft or if blowing dust/snow could obscure visibility. If it is necessary to operate above 25 feet AGL when hover taxiing…