FH.II.D.K3

From the FAA library

• Helicopter Flying Handbookp. G-5
  Glossary

  rotation. Torque. In helicopters with a single, main rotor system, the tendency of the helicopter to turn in the opposite direction of the main rotor rotation. Trailing edge. The rearmost edge of an airfoil. Translating tendency. The tendency ... laterally during hovering flight. Also called tail rotor drift. Translational lift. The additional lift obtained when entering forward flight, due to the increased efficiency of the rotor system. Transverse-flow effect. The condition of increased drag and decreased lift…

• 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 ... 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 to move the helicopter laterally. The main transmission is mounted…

• Helicopter Flying Handbookp. 2-21
  Chapter 2: Aerodynamics of Flight › Forward Flight › Effective Translational Lift (ETL)

  Translational Lift Improved rotor efficiency resulting from directional flight is called translational lift. The efficiency of the hovering rotor disk is greatly improved with each knot of incoming wind gained by horizontal movement of the aircraft or surface wind ... efficiency of the tail rotor. Figure 2-38. To compensate for blowback, you must move the cyclic forward. Effective Translational Lift (ETL) While transitioning to forward flight at about 16 to 24 knots, the helicopter goes through effective translational lift…

• Helicopter Flying Handbookp. 2-22
  Chapter 2: Aerodynamics of Flight › Forward Flight › Translational Thrust

  airspeed until the best climb airspeed is reached, and total drag is at its lowest point. As speed increases, translational lift becomes more effective, nose rises or pitches up, and aircraft rolls to the right. The combined effects of dissymmetry ... lift, gyroscopic precession, and transverse flow effect cause this tendency. It is important to understand these effects and anticipate correcting for them. Once the helicopter is transitioning through ETL, the pilot needs to apply forward and left lateral cyclic input…

• Helicopter Flying Handbookp. 2-23
  Chapter 2: Aerodynamics of Flight › Translational Thrust › Transverse Flow Effect

  Transverse Flow Effect As the helicopter accelerates in forward flight, induced flow drops to near zero at the forward disk area and increases at the aft disk area. These differences in lift between the fore and aft portions ... rotor disk are called transverse flow effect. [Figure 2-41] This increases the AOA at the front disk area causing the rotor blade to flap up and reduces AOA at the aft disk area causing the rotor blade to flap…

• Aviation Maintenance Technician Handbook - Airframep. 2-18
  Chapter 2: Aerodynamics, Aircraft Assembly, & Rigging › Forces Acting on the Helicopter › Torque Compensation

  Torque Compensation Newton’s third law of motion states “To every action there is an equal and opposite reaction.” As the main rotor of a helicopter turns in one direction, the fuselage tends to rotate in the opposite direction. This ... tendency for the fuselage to rotate is called torque. Since torque effect on the fuselage is a direct result of engine power supplied to the main rotor, any change in engine power brings about a corresponding change in torque effect…