This SAE Aerospace Recommended Practice (ARP) covers the design and installation requirements for hydraulic systems (up to 8000 psig [56 MPa]) for ground support equipment (GSE). The GSE may be portable or stationary.The hydraulic systems defined by this document shall be capable of servicing aircraft systems and components of all types and classes defined in MIL-H-5440. The terminology, Class XXXX, where XXXX is the GSE system pressure, is utilized within this document.