Aircraft Hydraulic and Pneumatic power system Syllabus Diploma in Aircraft Maintenance Engineering, Regulation 2010:

  • To provide basic knowledge on principle of hydraulic fluid.
  • To list the properties and characteristics of different types of hydraulic fluids.
  • To make familiar with the fluid contamination and its control.
  • To give guidance on basic hydraulic system and system variations.
  • To provide general knowledge about construction and operation of different components.
  • To make familiar with the system control, indication and warning devices.
  • To give guideline on hydraulic system maintenance procedure.
  • To provide introductory idea about the sources and characteristics of air lender pressure.
  • To know the use of pneumatic system with different pressure surge.
  • To make familiar with the purpose, function and construction of each component used in pneumatic system.
  • To provide guideline about the pneumatic system inspection, maintenance and servicing procedure.
  • To know the advantages of pneumatic system over hydraulic system.



Introduction to basic principle, properties and contamination control of hydraulic fluid, function and operation of system components, control, indication and system maintenance procedure etc.

To provide introductory idea about the characteristics of pressurized air, its use, purpose function and construction of system components, inspection, maintenance & servicing etc





Aircraft Hydraulic System


  1. Understand the following basic principle (fluid)

1.1        Compressibility

1.2        Pressure

1.3        Pascal’s law

1.4        Force due to fluid pressure

1.5        Brahma’s press

  1. Outline the properties of hydraulic fluid:

2.1        Define viscosity and high viscosity index.

2.2        Define freezing and high boiling points.

2.3        Describe the chemical effect of fluid on the materials in the components.

2.4        lubrication quality

2.5        Explain chemically stable. (Not to deteriorate time effect or form sludge)

2.6        Define flash point

2.7        Define fire point

2.8        Explain toxicity & non-toxic

2.9        Describe non-flaming

  1. List the difference amongst the following types of hydraulic fluid:

3.1        Vegetable base hydraulic fluid.

3.2        Mineral base hydraulic fluid.

3.3        Phosphate ester base hydraulic fluid.

  1. Distinguish the hydraulic fluid contamination:

4.1        Abrasives.

4.2        Non-abrasive

4.3        Contamination check

4.4        Contamination control

  1. Describe basic hydraulic system:

5.1        Four main sections of hydraulic system.

5.1.1     Sketch power section

5.1.2     Sketch control section

5.1.3     Sketch fluid distribution section

5.1.4     Sketch actuating section

  1. Outline the variations of following hydraulic systems:

6.1        Open centre hydraulic system

6.2        Close centre hydraulic system.

  1. Describe the construction and operations of the following hydraulic systems components:

7.1        Hydraulic Reservoir.

7.1.1     Inline

7.1.2     Integral

7.2        Inline reservoir

7.2.1     Pressurized with air

7.2.2     Pressurized with hydraulic fluid

  1. Describe the construction and operations of hydraulic pumps:

8.1        Hand operated pump.

8.2        Power operated pump.

8.2.1     Power operated pumps  Low pressure pumps           Gear type pump           ‘Ge’ rotor type pump           Vane type pump

8.3.1     High pressure pumps  Piston type pumps  Constant delivery pump  Variable delivery pump

8.4        Pump drive coupling

  1. Describe the construction and operation of pressure regulator (cut-out valve)
  1. Describe the operations of pressure relief valve:

10.1      Two ported pressure relief.

10.2      Four ported pressure relief.

10.3      Thermal relief valve.

  1. Describe the operations of hydraulic filter:

11.1      Felt type.

11.2      Micronics type

11.3      Cuno-filter

11.4      Wire mesh filter.

  1. Describe the operations of hydraulic accumulators

12.1      Functions

12.2      Type accumulators

12.2.1   Spherical.            Diaphragm type accumulator.            Bladder type accumulator

12.2.2   Cylindrical            Piston type accumulators

12.2.3   Maintenance and servicing of accumulator

  1. Describe the operations of check valves:

13.1      Ball type check valve

13.2      Cone type check valve

13.3      Swing type check valve

13.4      Orifice type check valve

  1. Describe the operations of selector valves:

14.1      Open centre type

14.2      Closed centre type

14.2.1   Four way closed centre selector valve (Rotary)

14.2.2   Spool type closed centre selector valve (cylindrical)

  1. Describe priority valve
  1. Describe sequence valve
  1. Describe shuttle valve
  1. Describe hydraulic motor
  1. Describe quick disconnect (coupling) valve (line disconnect):
  1. Describe hydraulic fuse
  1. Understand the operation and difference of the following actuators:

21.1      Function.

21.2      Type

21.2.1   Single acting actuator

21.2.2   Double acting actuator

21.2.3   Balance type actuator

  1. Familiar with control indication and warning devices
  1. Hydraulic system maintenance and servicing.
  1. Understand the system leak detection & protection.

24.1      Internal leaks

24.2      External leaks

Aircraft Pneumatic System

  1. Understand the characteristics of pressurized air:
  1. Understand the following pressure range variations:

26.1      High pressure system.

26.2      Medium pressure system.

26.3      Low pressure system.

  1. Describe the following sources of pneumatic power:

27.1      Engine driven compressor (4 stages) piston Engine.

27.2      Engine bleed (Jet engine compressor bleed.)

27.3      Vane type air pump

27.4      Storage bottle.

  1. Describe the system pressure regulator:
  1. Describe the hydraulic system variations:
  1. Describe the manually operated control valve:
  1. Describe the pressure reducing valve:
  1. Describe the pressure reducing valve:
  1. Describe the check valves:
  1. Describe the restrictor:
  1. Describe the variable restrictor:
  1. Describe the relief valve:
  1. Describe the following filters:

37.1      Micronics filter.

37.2      Screen type filter

  1. Describe the selector valve:
  1. Describe the isolation valve:
  1. Describe the brake shuttle valve:
  1. Describe the ground charging valve:
  1. Describe the actuating cylinder (actuator)
  1. Describe the pneumatic system maintenance, inspection and servicing.










  1. Hydraulic Power System


1.1        Show skill in identify different types of hydraulic components

1.2        Show skill in removal & Installation of hydraulic pump, reservoir and accumulator

1.3        Show skill in disassemble, cleaning and reassemble of aircraft hydraulic filter

1.4        Show skill in disassemble, cleaning and reassemble of aircraft hydraulic actuator

  1. Pneumatic Power System


2.1        Show skill in identifying different types of Pneumatic components

2.2        Show skill in removal & Installation of pneumatic bottle

2.3        Show skill in disassemble, cleaning and reassemble of pneumatic filter & check valve Show skill in

2.4        Show skill in identifying components from Symbol.










Reference Books

  1. Haeco training manual

Australian training centre

2.         Airframe & Power Plant Mechanics

Airframe Hand book – AC 65-15A

Federal Aviation Administration (FAA)

3.         Aircraft Basic science by Bent & McKely

4.         Airframe & Power Plant Mechanics

General Hand book – AC 65-9A

Federal Aviation Administration (FAA)