Republic F-105B with avionics layout 060831-F-1234S-046

Avionics (a blend of ''aviation'' and ''electronics'') are the

electronic Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic co ...

systems used on

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engine ...

. Avionic systems include communications,

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, ...

, the display and management of multiple systems, and the hundreds of systems that are fitted to aircraft to perform individual functions. These can be as simple as a searchlight for a police helicopter or as complicated as the tactical system for an

airborne early warning Airborne or Airborn may refer to: Arts, entertainment, and media Films * ''Airborne'' (1962 film), a 1962 American film directed by James Landis * ''Airborne'' (1993 film), a comedy–drama film * ''Airborne'' (1998 film), an action film sta ...

platform.

History

The term "avionics" was coined in 1949 by Philip J. Klass, senior editor at '' Aviation Week & Space Technology'' magazine as a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of words Radio communication was first used in aircraft just prior to

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. The first airborne radios were in

zeppelin A Zeppelin is a type of rigid airship named after the German inventor Count Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp ...

s, but the military sparked development of light radio sets that could be carried by heavier-than-air craft, so that

aerial reconnaissance Aerial reconnaissance is reconnaissance for a military or strategic purpose that is conducted using reconnaissance aircraft. The role of reconnaissance can fulfil a variety of requirements including artillery spotting, the collection of i ...

biplanes could report their observations immediately in case they were shot down. The first experimental radio transmission from an airplane was conducted by the US Navy in August 1910. The first aircraft radios transmitted by radiotelegraphy, so they required two-seat aircraft with a second crewman to tap on a telegraph key to spell out messages by Morse code. During World War I, AM voice two way radio sets were made possible in 1917 by the development of the triode

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as ...

, which were simple enough that the pilot in a single seat aircraft could use it while flying.

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 ...

, the central technology used today in aircraft navigation and

air traffic control Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airs ...

, was developed by several nations, mainly in secret, as an air defense system in the 1930s during the runup to World War II. Many modern avionics have their origins in World War II wartime developments. For example,

autopilot An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...

systems that are commonplace today began as specialized systems to help bomber planes fly steadily enough to hit precision targets from high altitudes. Britain's 1940 decision to share its radar technology with its US ally, particularly the

magnetron The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while ...

, in the famous

Tizard Mission The Tizard Mission, officially the British Technical and Scientific Mission, was a British delegation that visited the United States during WWII to obtain the industrial resources to exploit the military potential of the research and development ( ...

, significantly shortened the war. Modern avionics is a substantial portion of military aircraft spending. Aircraft like the

F-15E The McDonnell Douglas (now Boeing) F-15E Strike Eagle is an American all-weather multirole strike fighter derived from the McDonnell Douglas F-15 Eagle. The F-15E was designed in the 1980s for long-range, high-speed interdiction without relyin ...

and the now retired F-14 have roughly 20 percent of their budget spent on avionics. Most modern

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

s now have budget splits of 60/40 in favour of avionics. The civilian market has also seen a growth in cost of avionics. Flight control systems (

fly-by-wire Fly-by-wire (FBW) is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals transmitted by wires, and flight control ...

) and new navigation needs brought on by tighter airspaces, have pushed up development costs. The major change has been the recent boom in consumer flying. As more people begin to use planes as their primary method of transportation, more elaborate methods of controlling aircraft safely in these high restrictive airspaces have been invented.

Modern avionics

Avionics plays a heavy role in modernization initiatives like the

Federal Aviation Administration The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic ...

's (FAA) Next Generation Air Transportation System project in the United States and the

Single European Sky ATM Research Single European Sky ATM Research (SESAR) is a collaborative project to completely overhaul European airspace and its air traffic management (ATM). The actual program is managed by the SESAR Joint Undertaking as a public–private partnership (PP ...

(SESAR) initiative in Europe. The

Joint Planning and Development Office The United States Congress established the Joint Planning and Development Office (JPDO) in 2003 to plan and coordinate the development of the Next Generation Air Transportation System (NextGen). The JPDO is a multi-agency public/private initiative ...

put forth a roadmap for avionics in six areas: * Published Routes and Procedures – Improved navigation and routing * Negotiated Trajectories – Adding data communications to create preferred routes dynamically * Delegated Separation – Enhanced situational awareness in the air and on the ground * LowVisibility/CeilingApproach/Departure – Allowing operations with weather constraints with less ground infrastructure * Surface Operations – To increase safety in approach and departure * ATM Efficiencies – Improving the ATM process

Market

The

Aircraft Electronics Association An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. ...

reports $1.73 billion avionics sales for the first three quarters of 2017 in business and

general aviation General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services ...

, a 4.1% yearly improvement: 73.5% came from North America, forward-fit represented 42.3% while 57.7% were

retrofit Retrofitting is the addition of new technology or features to older systems. Retrofits can happen for a number of reasons, for example with big capital expenditures like naval vessels, military equipment or manufacturing plants, businesses or go ...

s as the U.S. deadline of January 1, 2020 for mandatory ADS-B out approach.

Aircraft avionics

The cockpit of an aircraft is a typical location for avionic equipment, including control, monitoring, communication, navigation, weather, and anti-collision systems. The majority of aircraft power their avionics using 14- or 28‑volt DC electrical systems; however, larger, more sophisticated aircraft (such as airliners or military combat aircraft) have AC systems operating at 400 Hz, 115 volts AC. There are several major vendors of flight avionics, including

The Boeing Company The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and product ...

, Panasonic Avionics Corporation, Honeywell (which now owns Bendix/King), Universal Avionics Systems Corporation, Rockwell Collins (now Collins Aerospace), Thales Group,

GE Aviation Systems GE Aviation Systems (formerly Smiths Aerospace) is an American aerospace engineering, aircraft engine and aircraft parts manufacturer. Smiths Aerospace was formerly one of four business units of Smiths Group plc., an engineering company and cons ...

Garmin Garmin Ltd. (shortened to Garmin, stylized as GARMIN, and formerly known as ProNav) is an American, Swiss-domiciled multinational technology company founded in 1989 by Gary Burrell and Min Kao in Lenexa, Kansas, United States, with headquarte ...

Raytheon Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitali ...

Parker Hannifin Parker Hannifin Corporation, originally Parker Appliance Company, usually referred to as just Parker, is an American corporation specializing in motion and control technologies. Its corporate headquarters are in Mayfield Heights, Ohio, in Greate ...

, UTC Aerospace Systems (now Collins Aerospace),

Selex ES Selex ES was a subsidiary of Finmeccanica S.p.A., active in the electronics and information technology business, based in Italy and the United Kingdom, UK, and formed in January 2013, following Finmeccanica's decision to combine its existing SE ...

(now Leonardo S.p.A.), Shadin Avionics, and

Avidyne Corporation Avidyne Corporation is an avionics company based in Melbourne, Florida. Avidyne is developer of Integrated Avionics Systems, multi-function displays, and traffic advisory systems for light general aviation (GA) aircraft. Headquartered in Melbou ...

. International standards for avionics equipment are prepared by the Airlines Electronic Engineering Committee (AEEC) and published by ARINC.

Communications

Communications connect the flight deck to the ground and the flight deck to the passengers. On‑board communications are provided by public-address systems and aircraft intercoms. The VHF aviation communication system works on the

airband Airband or aircraft band is the name for a group of frequencies in the VHF radio spectrum allocated to radio communication in civil aviation, sometimes also referred to as ''VHF'', or phonetically as ''"Victor"''. Different sections of the band ...

of 118.000 MHz to 136.975 MHz. Each channel is spaced from the adjacent ones by 8.33 kHz in Europe, 25 kHz elsewhere. VHF is also used for line of sight communication such as aircraft-to-aircraft and aircraft-to-ATC. Amplitude modulation (AM) is used, and the conversation is performed in simplex mode. Aircraft communication can also take place using HF (especially for trans-oceanic flights) or satellite communication.

Navigation

Air navigation is the determination of position and direction on or above the surface of the Earth. Avionics can use satellite navigation systems (such as

GPS The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

and

WAAS The Wide Area Augmentation System (WAAS) is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity, and availability. Essentia ...

), inertial navigation system (INS), ground-based

radio navigation Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination. The basic principles a ...

systems (such as VOR or LORAN), or any combination thereof. Some navigation systems such as GPS calculate the position automatically and display it to the flight crew on moving map displays. Older ground-based Navigation systems such as VOR or LORAN requires a pilot or navigator to plot the intersection of signals on a paper map to determine an aircraft's location; modern systems calculate the position automatically and display it to the flight crew on moving map displays.

Monitoring

The first hints of glass cockpits emerged in the 1970s when flight-worthy cathode ray tube (CRT) screens began to replace electromechanical displays, gauges and instruments. A "glass" cockpit refers to the use of computer monitors instead of gauges and other analog displays. Aircraft were getting progressively more displays, dials and information dashboards that eventually competed for space and pilot attention. In the 1970s, the average aircraft had more than 100 cockpit instruments and controls.''Avionics: Development and Implementation'' by Cary R. Spitzer (Hardcover – December 15, 2006) Glass cockpits started to come into being with the Gulfstream G‑IV private jet in 1985. One of the key challenges in glass cockpits is to balance how much control is automated and how much the pilot should do manually. Generally they try to automate flight operations while keeping the pilot constantly informed.

Aircraft flight-control system

Aircraft have means of automatically controlling flight.

Autopilot An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...

was first invented by

Lawrence Sperry Lawrence Burst Sperry (21 December 1892, Chicago, Illinois, United States – December 13, 1923, English Channel) was an aviation pioneer who invented the autopilot and the artificial horizon. Biography He was the third son of the gyrocompa ...

during World War I to fly bomber planes steady enough to hit accurate targets from 25,000 feet. When it was first adopted by the U.S. military, a Honeywell engineer sat in the back seat with bolt cutters to disconnect the autopilot in case of emergency. Nowadays most commercial planes are equipped with aircraft flight control systems in order to reduce pilot error and workload at landing or takeoff.By Jeffrey L. Rodengen. . Published by Write Stuff Syndicate, Inc. in 1995. "The Legend of Honeywell." The first simple commercial auto-pilots were used to control heading and altitude and had limited authority on things like

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...

and flight control surfaces. In

s, auto-stabilization was used in a similar way. The first systems were electromechanical. The advent of

and electro-actuated flight surfaces (rather than the traditional hydraulic) has increased safety. As with displays and instruments, critical devices that were electro-mechanical had a finite life. With safety critical systems, the software is very strictly tested.

Fuel Systems

Fuel Quantity Indication System (FQIS) monitors the amount of fuel aboard. Using various sensors, such as capacitance tubes, temperature sensors, densitometers & level sensors, the FQIS computer calculates the mass of fuel remaining on board. Fuel Control and Monitoring System (FCMS) reports fuel remaining on board in a similar manner, but, by controlling pumps & valves, also manages fuel transfers around various tanks. * Refuelling control to upload to a certain total mass of fuel and distribute it automatically. * Transfers during flight to the tanks that feed the engines. E.G. from fuselage to wing tanks * Centre of gravity control transfers from the tail (trim) tanks forward to the wings as fuel is expended * Maintaining fuel in the wing tips (to help stop the wings bending due to lift in flight) & transferring to the main tanks after landing * Controlling fuel jettison during an emergency to reduce the aircraft weight.

Collision-avoidance systems

To supplement

, most large transport aircraft and many smaller ones use a traffic alert and collision avoidance system (TCAS), which can detect the location of nearby aircraft, and provide instructions for avoiding a midair collision. Smaller aircraft may use simpler traffic alerting systems such as TPAS, which are passive (they do not actively interrogate the

transponder In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight trans ...

s of other aircraft) and do not provide advisories for conflict resolution. To help avoid controlled flight into terrain ( CFIT), aircraft use systems such as ground-proximity warning systems (GPWS), which use radar altimeters as a key element. One of the major weaknesses of GPWS is the lack of "look-ahead" information, because it only provides altitude above terrain "look-down". In order to overcome this weakness, modern aircraft use a terrain awareness warning system ( TAWS).

Flight recorders

Commercial aircraft cockpit data recorders, commonly known as "black boxes", store flight information and audio from the cockpit. They are often recovered from an aircraft after a crash to determine control settings and other parameters during the incident.

Weather systems

Weather systems such as weather radar (typically Arinc 708 on commercial aircraft) and

lightning detector A lightning detector is a device that detects lightning produced by thunderstorms. There are three primary types of detectors: ''ground-based'' systems using multiple antennas, ''mobile systems'' using a direction and a sense antenna in the same l ...

s are important for aircraft flying at night or in instrument meteorological conditions, where it is not possible for pilots to see the weather ahead. Heavy precipitation (as sensed by radar) or severe turbulence (as sensed by lightning activity) are both indications of strong convective activity and severe turbulence, and weather systems allow pilots to deviate around these areas. Lightning detectors like the Stormscope or Strikefinder have become inexpensive enough that they are practical for light aircraft. In addition to radar and lightning detection, observations and extended radar pictures (such as

NEXRAD NEXRAD or Nexrad (Next-Generation Radar) is a network of 160 high-resolution S-band Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) within the United S ...

) are now available through satellite data connections, allowing pilots to see weather conditions far beyond the range of their own in-flight systems. Modern displays allow weather information to be integrated with moving maps, terrain, and traffic onto a single screen, greatly simplifying navigation. Modern weather systems also include

wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizont ...

and turbulence detection and terrain and traffic warning systems. In‑plane weather avionics are especially popular in Africa,

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, and other countries where air-travel is a growing market, but ground support is not as well developed.

Aircraft management systems

There has been a progression towards centralized control of the multiple complex systems fitted to aircraft, including engine monitoring and management. Health and usage monitoring systems (HUMS) are integrated with aircraft management computers to give maintainers early warnings of parts that will need replacement. The integrated modular avionics concept proposes an integrated architecture with application software portable across an assembly of common hardware modules. It has been used in

fourth generation jet fighter The fourth-generation fighter is a Jet fighter generations, class of jet fighters in service from around 1980 to the present, and represents design concepts of the 1970s. Fourth-Jet fighter generations, generation designs are heavily influenced ...

s and the latest generation of airliners.

Mission or tactical avionics

Military aircraft have been designed either to deliver a weapon or to be the eyes and ears of other weapon systems. The vast array of sensors available to the military is used for whatever tactical means required. As with aircraft management, the bigger sensor platforms (like the E‑3D, JSTARS, ASTOR, Nimrod MRA4, Merlin HM Mk 1) have mission-management computers. Police and EMS aircraft also carry sophisticated tactical sensors.

Military communications

While aircraft communications provide the backbone for safe flight, the tactical systems are designed to withstand the rigors of the battle field. UHF, VHF Tactical (30–88 MHz) and SatCom systems combined with ECCM methods, and cryptography secure the communications. Data links such as

Link 11 TADIL-A/Link 11 is a secure half-duplex tactical data link used by NATO to exchange digital data. It was originally developed by a joint committee including members from the Canadian Navy, US Navy and Royal Navy to pass accurate targeting inform ...

, 16, 22 and BOWMAN, JTRS and even

TETRA Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by ...

provide the means of transmitting data (such as images, targeting information etc.).

Radar

Airborne

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 ...

was one of the first tactical sensors. The benefit of altitude providing range has meant a significant focus on airborne radar technologies. Radars include

(AEW),

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are t ...

(ASW), and even weather radar ( Arinc 708) and ground tracking/proximity radar. The military uses radar in fast jets to help pilots fly at low levels. While the civil market has had weather radar for a while, there are strict rules about using it to navigate the aircraft.

Sonar

Dipping sonar fitted to a range of military helicopters allows the

to protect shipping assets from submarines or surface threats. Maritime support aircraft can drop active and passive sonar devices (

sonobuoy A sonobuoy (a portmanteau of sonar and buoy) is a relatively small buoy – typically diameter and long – expendable sonar system that is dropped/ejected from aircraft or ships conducting anti-submarine warfare or underwater acoustic rese ...

s) and these are also used to determine the location of enemy submarines.

Electro-optics

Electro-optic systems include devices such as the

head-up display A head-up display, or heads-up display, also known as a HUD (), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view informa ...

(HUD), forward looking infrared (FLIR),

infrared search and track An infrared search and track (IRST) system (sometimes known as infrared sighting and tracking) is a method for detecting and tracking objects which give off infrared radiation, such as the infrared signatures of jet aircraft and helicopters. IR ...

and other passive infrared devices ( Passive infrared sensor). These are all used to provide imagery and information to the flight crew. This imagery is used for everything from search and rescue to navigational aids and target acquisition.

ESM/DAS

Electronic support measures and defensive aids systems are used extensively to gather information about threats or possible threats. They can be used to launch devices (in some cases automatically) to counter direct threats against the aircraft. They are also used to determine the state of a threat and identify it.

Aircraft networks

The avionics systems in military, commercial and advanced models of civilian aircraft are interconnected using an avionics databus. Common avionics databus protocols, with their primary application, include: *

Aircraft Data Network Aircraft Data Network (ADN) is a concept introduced by the Airlines Electronics Engineering Committee (AEEC) in the ARINC 664 Specification. The specification proposes data networking standards recommended for use in commercial aircraft installat ...

( ADN): Ethernet derivative for Commercial Aircraft * Avionics Full-Duplex Switched Ethernet (AFDX): Specific implementation of ARINC 664 ( ADN) for Commercial Aircraft *

ARINC 429 ARINC 429, "Mark33 Digital Information Transfer System (DITS)," is also known as the Aeronautical Radio INC. (ARINC) technical standard for the predominant avionics data bus used on most higher-end commercial and transport aircraft. It defines the ...

: Generic Medium-Speed Data Sharing for Private and Commercial Aircraft * ARINC 664: See ADN above * ARINC 629: Commercial Aircraft (

Boeing 777 The Boeing 777, commonly referred to as the Triple Seven, is an American long-range wide-body airliner developed and manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet. The 777 was designed to bridge the gap betw ...

) * ARINC 708: Weather Radar for Commercial Aircraft *

ARINC 717 ARINC 717 defines a digital flight data recorder, with its inputs and outputs. It replaces the older ARINC 573 characteristic, which was based on analog inputs. It allows for more data and real-time recording. Digital Expandable Flight Data Acq ...

: Flight Data Recorder for Commercial Aircraft *

ARINC 825 Aeronautical Radio, Incorporated (ARINC), established in 1929, was a major provider of transport communications and systems engineering solutions for eight industries: aviation, airports, defense, government, healthcare, networks, security, and t ...

: CAN bus for commercial aircraft (for example

Boeing 787 The Boeing 787 Dreamliner is an American wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, ...

and

Airbus A350 The Airbus A350 is a long-range, wide-body twin-engine jet airliner developed and produced by Airbus. The first A350 design proposed by Airbus in 2004, in response to the Boeing 787 Dreamliner, would have been a development of the A330 ...

) * Commercial Standard Digital Bus *

IEEE 1394b IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony and ...

: Military Aircraft * MIL-STD-1553: Military Aircraft * MIL-STD-1760: Military Aircraft * TTP – Time-Triggered Protocol:

, Airbus A380, Fly-By-Wire Actuation Platforms from Parker Aerospace

Notes

External links

Avionics in Commercial AircraftAircraft Electronics Association (AEA)''Pilot's Guide to Avionics''The Avionic Systems Standardisation CommitteeAviation Today Avionics magazineRAES Avionics homepage
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