Glossary Terms

Hydraulic Actuator

a mechanical device that is used to give a unidirectional force through a unidirectional stroke. (Wikipedia)

Hydraulic Manifold

a component that regulates fluid flow between pumps and actuators and other components in a hydraulic system (Wikipedia)

Hydraulic Pump

a mechanical sources of power that converts mechanical power into hydraulic energy. It generates flow with enough power to overcome pressure induced by the load at the pump outlet. (Wikipedia)

LRU – Line Replaceable Unit

modular component of an airplane that is designed to be replaced quickly at an operating location (Wikipedia)


Inspection, overhaul, repair, preservation, and replacement of parts, but excludes preventive maintenance (14CRF1.1)

Major Repair

A repair (1) `that, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or (2) that is not done according to accepted practices or cannot be done by elementary operations (14CFR1.1)

Minor Repair

Anything other than a major repair (14CFR1.1)


a process that consists of disassembly, cleaning, inspection, repaired as necessary, reassembly, and testing. (14CFR21.1)

Quality System

A network of administrative processes and procedures whose purpose is to protect aircraft parts from damage or degradation, to preserve documentation associated with those parts, and to satisfy customers that purchase or obtain those parts. (ASA)


Track parts, processes, and materials to a source. (ASA)