PCU's and Hydraulic Actuators/ Aileron Feel

[torquetubes1]

747 Classic:

Trailing Edge Flaps: Is Power Control Unit just another name for Hydraulic Actuator?

Aileron Feel: Is Aileron Feel merely controlled by a spring -the more you turn the control column, the greater the tension on the spring? Is it that simple, unlike the elevator and rudder which have their own seperate Feel Units??

[gas path]

Trailing Edge Flaps: Is Power Control Unit just another name for Hydraulic Actuator?
Mr. Boeings AMM calls it (them! because there is one for the outboard trailing edge flaps and one for the inboard!)
Inboard (or outboard) flap power package.
FYI they are operated by cable from the flt deck lever to a quadrant in the wheel well and rods connect the flap power packages to the quadrant. On selecting a flap position the mechanical selection repositions the control valves which port the hyd. power to hyd. motors.
Aileron Feel: Is Aileron Feel merely controlled by a spring -the more you turn the control column, the greater the tension on the spring? Is it that simple, unlike the elevator and rudder which have their own seperate Feel Units??
In short Yes! The control cables go to the l/hand wheel well to a cable quadrant, this cable quadrant assy contains the aileron trim and feel mechanism.
The mechanism is basically a roller sitting in the dwell of a cam the more roll input applied the further up the cam the roller goes and the more it stretches a spring.
FYI the trim part of this mechanism just redatums the whole assy.

Moderators .... Was that ok or too much?


Not too sure why the question .... and I do not know the Type. Answering the question as you consider appropriate and within the bounds of your knowledge is all that we ask from a technical point of view ......

[QAVION]

"Aileron Feel: Is Aileron Feel merely controlled by a spring -the more you turn the control column, the greater the tension on the spring? Is it that simple, unlike the elevator and rudder which have their own seperate Feel Units??"

The 747 aileron system still has it's own individual feel (and trim and centering) unit. This is located in the left hand wing gear well. The rudder, as far as I know, has no force modification other than the mechanical cam and springs arrangement. The effective output, however, is modified by the rudder ratio system.

The elevator feel system, however, looks at airspeed and stab position to generate different feel at the control column end.

Hope this is correct.

Cheers.
Q.