CPL Acft Tech - Support systems

Pascal's principle states that if...

• pressure is applied at any point to a liquid in a closed system, that same pressure is felt throughout the system

• pressure is applied at any point to any substance in a closed system, that same pressure is felt throughout the system

• pressure is applied at any point to air in a closed system, that same pressure is felt throughout the system

• pressure is applied at any point to a solid in a closed system, that same pressure is felt throughout the system

Select all of the advantages of hydraulics over other systems

• relatively lightweight

• efficient

• not flammable

• minimal maintenance required

• fluid is non-corrosive

Vegetable based hydraulic oil is predominantly __________ oil and is made from the __________ _____________ plant

• castor , Ricinus communis

• schellac , Atropa belladonna

• castor , Papaver somniferum

• camfer , Coriandrum sativum

• camfer , Digitalis purpurea

What colour is mineral based hydraulic oil?

• Red

• Green

• Purple

• Blue

A disadvantage of synthetic based hydraulic fluid is it...

• attracts moisture

• is prone to forming sludge

• is unsuitable for higher pressures

• it is highly flammable

The purpose of a check valve in a hydraulic system is to...

• prevent the reverse flow of fluid

• limit the amount of pressure in a system

• initiate the movement of actuators in a system

• direct hydraulic fluid for system operation

What is the main source of contamination in a hydraulic system?

• Pump

• Actuators

• Check valve

• Accumulator

In a pressurised hydraulic system, an unloading valve...

• removes pressure from the pump when no service is required

• provides a safety release, venting fluid overboard if an overpressure occurs in the system

• converts pressure into mechanical energy

• allows pressure to flow from a diaphragm type accumulator to a bladder type accumulator

Pneumatic systems...

• are not suitable for precise control of moving parts

• present an explosion hazard

• are heavier than a comparable hydraulic system

• cope with moving large or heavy surfaces better than hydraulic systems

Pressures stored in a pneumatic system can be up to...

• 3000 psi

• 2000 psi

• 1000 psi

• 1500 psi