Theory of Rotary Wing Flight Practice Test

In an articulated rotor system, the plane of rotation tilts with respect to the helicopter body about the rotor hub, which serves as the reference for that tilt. The hub is the central rotating interface where all blades attach and through which flapping and lead-lag motions are transmitted; cyclic pitch commands are applied through this hub to each blade as they rotate. Because the hub is the common point connecting all blades and defining the rotor disk, it naturally acts as the tilting reference for the rotor plane. The mast is the drive shaft that powers the rotor and does rotate with the system, but the tilt of the disk is described relative to the hub rather than the mast. The blades themselves rotate about their own pitch axes and the skid is unrelated to the rotor’s tilt.