This specification covers the design and installation requirements for Types I and II aircraft hydraulic systems.

Classification

Aircraft hydraulic systems shall be of the following types and classes, as specified:

Types:

Type I Maximum fluid operating temperature +160°F (+71°C).

Type II Maximum fluid operating temperature +275°F (+135°C).

Classes

The class of operating pressure shall consist of the following:

a. Class 1500. 1500 psi (10 342 kPa) nominal operating pressure

b. Class 3000. 3000 psi (20 684 kPa) nominal operating pressure

c. Class 4000. 4000 psi (27 579 kPa) nominal operating pressure

d. Class 5000. 5000 psi (34 473 kPa) nominal operating pressure

e. Class 8000. 8000 psi (55 158 kPa) nominal operating pressure

For variable pressure level systems, such as 5000 psi and 3000 psi, the highest pressure shall determine the pressure class. The pressure class shall be annotated with a "V" to indicate variable pressures (example: class 5000V)