Patent ID: 6863239

Claim:
A fluid line for use in an active control device on a rotary wing aircraft having an airframe and a rotor rotatable relative to the airframe, the rotor including a hub and at least one elongated rotor blade connected at one end to the hub and extending radially outwardly therefrom such that when the rotor hub is rotatably driven the rotor blade rotates with the hub, the rotor blade movable relative to the hub about a blade pitch axis extending along its length, and a hydraulic actuation system for moving the blade about the blade pitch axis including a fluid source associated with the hub, means for controlling the position of the rotor blade about the blade pitch axis, and a hydraulic actuator operatively connected to and rotating with the blade for changing the position of the blade about the blade pitch axis in response to a signal from the controlling means, the fluid line comprising: a rigid member having a substantially helical shape with at least about two revolutions and a non-constant pitch length, said rigid member having a first end and a second end; a first fluid-tight connector fluidly connecting said first end of said rigid member to the fluid source; and a second fluid-tight connector fluidly connecting said second end of said rigid member to the hydraulic actuation system; wherein said first and second connectors are structured and arranged to non-releasably transmit forces generated in said rigid member to the hub and the rotor.