Which term defines the angular measure of blade pitch relative to the plane of rotation?

Which term defines the angular measure of blade pitch relative to the plane of rotation?

• A. NR
• B. Blade Angle
• C. Tip Path Plane
• D. CL

Answer: (B)

Blade angle is the angular measure of the blade’s pitch relative to the plane of rotation. It describes how much the blade is tilted from the rotor plane, as read from the blade’s chord line. This angle controls the thrust the blade produces: increasing the pitch tilts more lift into the rotor disc, boosting thrust (and drag) accordingly. The plane of rotation is the circular path the blade tip follows, but the term describing the blade’s tilt within that plane is blade angle. The other terms don’t describe this angular measure: Tip Path Plane refers to the orientation of the rotor disc itself, lift coefficient (CL) is a dimensionless number describing lift, and NR isn’t used for this purpose.

Blade angle is the angular measure of the blade’s pitch relative to the plane of rotation. It describes how much the blade is tilted from the rotor plane, as read from the blade’s chord line. This angle controls the thrust the blade produces: increasing the pitch tilts more lift into the rotor disc, boosting thrust (and drag) accordingly. The plane of rotation is the circular path the blade tip follows, but the term describing the blade’s tilt within that plane is blade angle. The other terms don’t describe this angular measure: Tip Path Plane refers to the orientation of the rotor disc itself, lift coefficient (CL) is a dimensionless number describing lift, and NR isn’t used for this purpose.