Aircraft systems are those required to operate an aircraft efficiently and safely. Their complexity varies with the type of aircraft.

Aircraft software systems

Aircraft software systems control, manage, and apply the subsystems that are engaged with avionics on board an aircraft.

Flight control systems

Flight control systems can be manually operated or powered. They are designed to move the

flight control surfaces Flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. The primary function of these is to control the aircraft's movement along the three axes of rotation. Flight control surfaces ...

swashplate A swashplate, also known as slant disk, is a mechanical engineering device used to translate the motion of a rotating shaft into reciprocating motion, or vice versa. The working principle is similar to crankshaft, Scotch yoke, or wobble, nutat ...

, allowing the pilot to maintain or change attitude as required.

Landing gear system

Landing gear systems for larger aircraft are usually hydraulic for powered retraction/extension of the main legs and doors and also for braking. Anti-skid systems are used to provide maximum braking performance.

Hydraulic system

hydraulic Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

system is required for high speed flight and large aircraft to convert the crews' control system movements to surface movements. The hydraulic system is also used to extend and retract landing gear, operate flaps and slats, operate the wheel brakes and steering systems. Hydraulic systems consist of engine driven pumps, fluid reservoirs, oil coolers, valves and

actuators An actuator is a component of a machine that produces force, torque, or displacement, when an electrical, pneumatic or hydraulic input is supplied to it in a system (called an actuating system). The effect is usually produced in a controlled way. ...

. Redundancy for safety is often provided by the use of multiple, isolated systems.Taylor 1990, p. 167.

Electrical system

The electrical system generally consist of a battery, generator or

alternator An alternator (or synchronous generator) is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field wit ...

, switches,

circuit breaker A circuit breaker is an electrical safety device designed to protect an Electrical network, electrical circuit from damage caused by current in excess of that which the equipment can safely carry (overcurrent). Its basic function is to interr ...

s and instruments such as

voltmeter A voltmeter is an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel. It usually has a high resistance so that it takes negligible current from the circuit. A ...

s and

ammeter An ammeter (abbreviation of ''ampere meter'') is an measuring instrument, instrument used to measure the electric current, current in a Electrical circuit, circuit. Electric currents are measured in amperes (A), hence the name. For direct measure ...

s. Back up electrical supply can be provided by a ram air turbine (RAT) or

Hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly hazardous unless handled in solution as, for example, hydraz ...

powered turbines.

Engine bleed air system

Bleed air is

compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air in vehicle tires and shock absorbers are commonly used for improved traction and reduced vibration. Compressed air is an important medium for t ...

taken from the compressor stage of a

gas turbine A gas turbine or gas turbine engine is a type of Internal combustion engine#Continuous combustion, continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas gene ...

engine upstream of its fuel-burning sections. It is used for several purposes which include cabin pressurisation, cabin heating or cooling,

boundary layer control In engineering, boundary layer control refers to methods of controlling the behaviour of fluid flow boundary layers. It may be desirable to reduce flow separation on fast vehicles to reduce the size of the wake (streamlining), which may reduce ...

(BLC), ice protection and pressurisation of fuel tanks.

Avionics

Aircraft avionic systems encompass a wide range of electrical and electronic systems that include flight instruments, radios, and navigation systems.

Environmental control system or Cabin control system

Aircraft environmental control systems (ECS) provide cabin pressurisation and heating while also providing cooling for electronic systems such as

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

Fuel systems

An aircraft fuel system is designed to store and deliver

aviation fuel Aviation fuels are either petroleum-based or blends of petroleum and synthetic fuels, used to power aircraft. They have more stringent requirements than fuels used for ground applications, such as heating and road transport, and they contain add ...

to the propulsion system and

auxiliary power unit An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115&n ...

(APU) if equipped. Fuel systems differ greatly due to different performance of the aircraft in which they are installed.

Propulsion systems

Propulsion systems encompass engine installations and their controls. Sub-systems include fire detection and protection and

thrust reversal Thrust reversal, also called reverse thrust, is the temporary diversion of an aircraft engine's thrust for it to act against the forward travel of the aircraft, providing deceleration. Thrust reverser systems are featured on many jet aircraft to ...

Ice protection systems

Aircraft that regularly operate in icing conditions have systems to detect and prevent ice forming (anti-icing) and/or remove the ice accumulation after it has formed (de-icing). This can be achieved by heating the spaces in internal structure with engine bleed air, chemical treatment, electrical heating and expansion/contraction of the skin using de-icing boots.Rolls-Royce 1966, p.115.

References

Citations

Bibliography

* Rolls-Royce. ''The jet engine.'' Second edition, Derby, Rolls-Royce Limited, 1966. * Taylor, John W.R. ''The Lore of Flight'', London: Universal Books Ltd., 1990. . {{DEFAULTSORT:Aircraft Systems