Card Set Information

2014-03-06 04:11:07

Show Answers:

  1. Describe the term Tip Path Plane
    The circular path scribed by the tips of the rotor blade. It is parallel to the Plane of Rotation (POR) that acts through the rotor head
  2. Define Coning Angle
    The angle between the Plane of Rotation and the Blades
  3. Describe the Angle of Attack
    The angle between the Chord line and the relative airflow
  4. What are the two combinations of two forces create the Total Reaction
    Lift and Drag, or Rotor drag and rotor thrust.
  5. Describe Flapping to Equality.......yep
    Someone who has a good answer here...go nuts
  6. What are the 3 causes of dragging in an articulated rotor system
    • Changing of blade radius of rotation
    • hookes joint effect
    • Periodic drag changes
  7. Describe the changing blade radius of rotation
    When the rotor blades are allowed to flap there is a slight change in radius of the path, the blade C of G follows......ballerina spinning example
  8. What is tail rotor drift
    The torque force is created by the main rotors spinning counter clockwise, causing the main body of the Helo to want to rotate clockwise, but both twisting motions are about a single central point - the tail rotor is positioned on a moment arm out to the rear of the helo and even thou it provides an antitorque force, the force pushes the A/C sideways - this is known as tail rotor drift
  9. What is Tail Rotor Roll
    Tail rotor opposes the main rotor torque - Because the tail rotor is mounted below the level of the main rotor a moment arm is created causing a rolling motion - this causes the Helo to hover one wheel low
  10. Describe what ground effect is
    This is when the downwash from the rotor meets the ground and cannot escape, this creates a cushion of air under the A/C - the cushion reduces the induced flow so total thrust for a given power setting is increased
  11. Describe Translational Lift
    This is lift that is created by an A/C reducing the induced flow created in a hover, exposing the disc to clear air. Angle of attack is increased and total thrust is increased