Basic Hydraulic Principles
Hydraulic systems provide a means of remotely controlling a wide range
of components by transmitting a force through a confined fluid.
Because hydraulics can transmit high forces rapidly and accurately along
lightweight pipes of any size, shape and length, they are the prime source
of power in aircraft systems such as flying controls, retractable
undercarriages, flaps, and wheelbrakes.
The basic principle behind any hydraulic system is very simple - pressure
applied anywhere to a body of fluid causes a force to be transmitted equally
in all directions, with the force acting at right angles to any surface
in contact with the fluid. This is known as Pascals Law.