PH.VI.C.S8

From the FAA library

• Helicopter Flying Handbookp. 4-11
  Chapter 4: Helicopter Components, Sections, and Systems › Transmission System › Dual Tachometers

  NR) on the left and engine rpm (NP) on the right side of the vertical scale. Corresponding color limits are present for each component parameter. Structural Design In helicopters with horizontally mounted engines, another purpose of the main rotor transmission ... divided needle condition is a result of a sudden loss of engine power. Maintaining main rotor rpm is essential for adequate lift. RPM within normal limits produces adequate lift for normal maneuvering. Therefore, it is imperative not only to know…

• Helicopter Flying Handbookp. 1-4
  Chapter 1: Introduction to the Helicopter › Rotor System › Tandem Rotor

  Tandem Rotor Tandem rotor (sometimes referred to as dual rotor) helicopters have two large horizontal rotor assemblies, instead of one main assembly and a smaller tail rotor. [Figure 1-6] Single rotor helicopters need a tail rotor to neutralize ... twisting momentum produced by the single large rotor. Tandem rotor helicopters, however, use counter-rotating rotors, each canceling out the other’s torque. Counter-rotating rotor blades will not collide with and destroy each other if they flex into…

• Helicopter Flying Handbookp. 11-21
  Chapter 11: Helicopter Emergencies and Hazards › Recovery Technique (Uncontrolled Right Yaw) › Main Drive Shaft or Clutch Failure

  Main Drive Shaft or Clutch Failure The main drive shaft, located between the engine and the main rotor transmission, provides engine power to the main rotor transmission. In some helicopters, particularly those with piston engines, a drive belt is used ... clutch or belt has the same effect as an engine failure because power is no longer provided to the main rotor and an autorotation must be initiated. There are a few differences, however, that need to be taken into consideration…

• 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. 1-4
  Chapter 1: Introduction to the Helicopter › Rotor System › Intermeshing Rotors

  Coaxial Rotors Coaxial rotors are a pair of rotors turning in opposite directions, but mounted on a mast, with the same axis of rotation, one above the other. This configuration is a noted feature of helicopters produced by the Russian ... Kamov helicopter design bureau. [Figure 1-7] Intermeshing Rotors Intermeshing rotors on a helicopter are a set of two rotors turning in opposite directions, with each rotor mast mounted on the helicopter with a slight angle to the other…

• Aviation Maintenance Technician Handbook - Airframep. 2-26
  Chapter 2: Aerodynamics, Aircraft Assembly, & Rigging › Helicopter Flight Conditions › Autorotation

  further increases pitch angle on the retreating blade. As a result, there is even more tilt to the rotor than at lower speeds. Figure 2-42. To compensate for blowback, move the cyclic forward. Blowback is more pronounced with higher ... airspeeds. This horizontal lift component (thrust) generates higher helicopter airspeed. The higher airspeed induces blade flapping to maintain symmetry of lift. The combination of flapping and cyclic feathering maintains symmetry of lift and desired attitude on the rotor system…