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 onboard an aircraft.

Flight control systems

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

flight control surfaces Aircraft flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. Development of an effective set of flight control surfaces was a critical advance in the development of aircraft. Ea ...

or swashplate, 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 (from Greek: Υδραυλική) 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 counte ...

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 is responsible for moving and controlling a mechanism or system, for example by opening a valve. In simple terms, it is a "mover". An actuator requires a control device (controlled by control signal) an ...

. 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 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 with a stationary armature.Gor ...

, switches,

circuit breaker A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit. Its basic function is to interrupt current flow to protect equipment and to prevent the ris ...

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 instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. For direct measurement, the ammeter is connected in series with the circuit ...

s. Back up electrical supply can be provided by a

ram air turbine A ram air turbine (RAT) is a small wind turbine that is connected to a hydraulic pump, or electrical generator, installed in an aircraft and used as a power source. The RAT generates power from the airstream by ram pressure due to the speed o ...

(RAT) or Hydrazine powered turbines.

Engine bleed air system

Bleed air is compressed air taken from the compressor stage of a

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...

engine upstream of its fuel-burning sections. It is used for several purposes which include

cabin pressurisation Cabin pressurization is a process in which conditioned air is pumped into the cabin of an aircraft or spacecraft in order to create a safe and comfortable environment for passengers and crew flying at high altitudes. For aircraft, this air is u ...

, cabin heating or cooling,

boundary layer control 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 drag. Boundary l ...

(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 detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

Fuel systems

An aircraft fuel system is designed to store and deliver aviation fuel to the

propulsion system Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...

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& ...

(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 t ...

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