HI.VII.C.S5

From the FAA library

• Pilot's Handbook of Aeronautical Knowledgep. 5-44
  Chapter 5: Aerodynamics of Flight › High Speed Flight › Subsonic Versus Supersonic Flow

  Compressibility (and to a lesser extent viscosity) is of paramount importance at speeds approaching the speed of sound. In these speed ranges, compressibility causes a change in the density of the air around an aircraft. During flight, a wing produces ... lift by accelerating the airflow over the upper surface. This accelerated air can, and does, reach sonic speeds even though the aircraft itself may be flying subsonic. At some extreme AOAs, in some aircraft, the speed of the air over…

• Helicopter Flying Handbookp. 2-25
  Chapter 2: Aerodynamics of Flight › Turning Flight

  Figure 2-45. Forces acting on the helicopter during turning flight. Autorotation is the state of flight where the main rotor disk of a helicopter is being turned by the action of air moving up through the rotor rather than ... engine power driving the rotor. In normal, powered flight, air is drawn into the main rotor disk from above and exhausted downward, but during autorotation, air moves up into the rotor disk from below as the helicopter descends. Autorotation…

• Helicopter Flying Handbookp. 9-2
  Chapter 9: Basic Flight Maneuvers › The Four Fundamentals › Guidelines

  Good practices to follow during maneuvering flight include: 1. Move the cyclic only as fast as trim, torque, and rotor speed can be maintained. When entering a maneuver and the trim, rotor, or torque reacts quicker than anticipated, pilot limitations ... have been exceeded. If continued, an aircraft limitation will be exceeded. Perform the maneuver with less intensity until all aspects of the machine can be controlled. The pilot must be aware of the sensitivity of the flight controls…

• Helicopter Flying Handbookp. 2-15
  Chapter 2: Aerodynamics of Flight › Hovering Flight › Translating Tendency (Drift)

  Translating Tendency (Drift) During hovering flight, a single main rotor helicopter tends to move in the direction of tail rotor thrust. This lateral (or sideward) movement is called translating tendency. [Figure 2-27] To counteract this tendency, one or more ... following features may be used. All examples are for a counterclockwise rotating main rotor disk. Figure 2-27. A tail rotor is designed to produce thrust in a direction opposite torque. The thrust produced by the tail rotor is sufficient…

• Pilot's Handbook of Aeronautical Knowledgep. 5-37
  Chapter 5: Aerodynamics of Flight › Load Factors › Rough Air

  extremely rough air, as in thunderstorms or frontal conditions, it is wise to reduce the speed to the design maneuvering speed. Regardless of the speed held, there may be gusts that can produce loads that exceed the load limits. Each ... imposed on the aircraft without causing structural damage. There are two types of load factors factored into aircraft design: limit load and ultimate load. The limit load is a force applied to an aircraft that causes a bending…

• Helicopter Flying Handbookp. 11-18
  Chapter 11: Helicopter Emergencies and Hazards › System Malfunctions › Loss of Tail Rotor Effectiveness (LTE)

  catastrophic. LTE is an aerodynamic condition and is the result of a control margin deficiency in the tail rotor. It can affect all single-rotor helicopters that utilize a tail rotor. The design of main and tail rotor blades ... will not nullify the phenomenon entirely. Translational lift is obtained by any amount of clean air through the main rotor disk. Chapter 2, Aerodynamics of Flight, discusses translational lift with respect to the main rotor blade, explaining that the more…