// LET'S STUDY AVIATION

Let's Study Aviation

Airframe Test A1 and Power Plant Test A4 — pick a subject and test yourself.

Aircraft Covering Aircraft Drawings Aircraft Electrical Systems Aircraft Finishes Aircraft Fuel Systems Aircraft Instrument Systems Aircraft Landing Gear Systems Airframe Inspection Assembly and Rigging Auxiliary Power Units Aviation Mechanic Privileges and Limitations Basic Electricity Basic Physics Cabin Atmosphere Control Systems Cleaning and Corrosion Control Communication and Navigation Systems Engine Cooling Systems Engine Electrical Systems Engine Exhaust and Reverser Systems Engine Fire Protection Systems Engine Fuel Systems Engine Inspection Engine Instrument Systems Fire Protection Systems Fluid Lines and Fittings Fuel Metering Systems Ground Operation and Servicing Hydraulic and Pneumatic Power Systems Ice and Rain Control Systems Ignition and Starting Systems Induction and Engine Airflow Systems Lubrication Systems Maintenance Forms and Records Maintenance Publications Materials and Processes Mathematics Position and Warning Systems Propellers Reciprocating Engines Sheet Metal and Non-Metallic Structures Turbine Engines Weight and Balance Welding Wood Structures

1 8400. What is the purpose of using backup rings with O-rings in hydraulic systems above 1,500 PSI?

A. Prevent internal and external leakage of all moving parts within a hydraulic system. B. Provide a seal between two parts of a unit which move in relation to each other. C. Prevent high pressure from extruding the seal between the moving and stationary part.