HI.II.D.K5

From the FAA library

• Helicopter Flying Handbookp. 4-3
  Chapter 4: Helicopter Components, Sections, and Systems › Main Rotor System › Semirigid Rotor System

  blades cone upward, the center of pressures of the blades are almost in the same plane as the hub. Whatever stresses are remaining bend the blades for compliance. Helicopters with semirigid rotors are vulnerable to a condition known as mast ... bumping which can cause the rotor flap stops to shear the mast. The mechanical design of the semirigid rotor system dictates downward flapping of the blades must have some physical limit. Mast bumping is the result of excessive rotor flapping…

• Helicopter Flying Handbookp. G-1
  Glossary

  Blade coning. An upward sweep of rotor blades as a result of lift and centrifugal force. Blade damper. A device attached to the drag hinge to restrain the fore and aft movement of the rotor blade. Blade feather or feathering ... rotation of the blade around the spanwise (pitch change) axis. Blade flap. The ability of the rotor blade to move in a vertical direction. Blades may flap independently or in unison. Blade grip. The part of the hub assembly…

• Pilot's Handbook of Aeronautical Knowledgep. G-7
  Glossary › Chart Supplement U.S. (formerly Airport/Facility

  turbine engines, a condition in an axial-flow compressor in which one or more stages of rotor blades fail to pass air smoothly to the succeeding stages. A stall condition is caused by a pressure ratio that is incompatible with ... liquid. Condensation nuclei. Small particles of solid matter in the air on which water vapor condenses. Cone of confusion. A cone-shaped volume of airspace directly above a VOR station where no signal is received, causing the CDI to fluctuate…