Editing Avionics (section)

==Aircraft avionics==
The cockpit or, in larger aircraft, under the cockpit of an aircraft or in a movable nosecone, is a typical location for [[Avionics bay|avionic bay]] equipment, including control, monitoring, communication, navigation, weather, and anti-collision systems. The majority of aircraft power their avionics using 14- or 28‑volt [[direct current|DC]] electrical systems; however, larger, more sophisticated aircraft (such as [[airliner]]s or military combat aircraft) have [[alternating current|AC]] systems operating at 115 volts 400&nbsp;Hz, AC.<ref>{{Cite web |url=http://www.aerospaceweb.org/question/electronics/q0219.shtml |title=400 Hz Electrical Systems |access-date=March 19, 2008 |archive-date=October 4, 2018 |archive-url=https://web.archive.org/web/20181004205311/http://www.aerospaceweb.org/question/electronics/q0219.shtml |url-status=live }}</ref> There are several major vendors of flight avionics, including [[The Boeing Company]], [[Panasonic Avionics Corporation]], [[Honeywell Aerospace|Honeywell]] (which now owns [[Bendix Aviation|Bendix/King]]), [[Universal Avionics Systems Corporation]], [[Rockwell Collins]] (now Collins Aerospace), [[Thales Group]], [[GE Aviation Systems]], [[Garmin]], [[Raytheon]], [[Parker Hannifin]], [[UTC Aerospace Systems]] (now Collins Aerospace), [[Selex ES]] (now [[Leonardo (company)|Leonardo]]), Shadin Avionics, and [[Avidyne Corporation]].

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

=== Avionics Installation ===
Avionics installation is a critical aspect of modern aviation, ensuring that aircraft are equipped with the necessary electronic systems for safe and efficient operation. These systems encompass a wide range of functions, including communication, navigation, monitoring, flight control, and weather detection. Avionics installations are performed on all types of aircraft, from small general aviation planes to large commercial jets and military aircraft.

==== Installation Process ====
The installation of avionics requires a combination of technical expertise, precision, and adherence to stringent regulatory standards. The process typically involves:
# '''Planning and Design''': Before installation, the avionics shop works closely with the aircraft owner to determine the required systems based on the aircraft type, intended use, and regulatory requirements. Custom instrument panels are often designed to accommodate the new systems.
# '''Wiring and Integration''': Avionics systems are integrated into the aircraft's electrical and control systems, with wiring often requiring laser marking for durability and identification. Shops use detailed schematics to ensure correct installation.
# '''Testing and Calibration''': After installation, each system must be thoroughly tested and calibrated to ensure proper function. This includes ground testing, flight testing, and system alignment with regulatory standards such as those set by the FAA.
# '''Certification''': Once the systems are installed and tested, the avionics shop completes the necessary certifications. In the U.S., this often involves compliance with FAA Part 91.411 and 91.413 for IFR (Instrument Flight Rules) operations, as well as RVSM (Reduced Vertical Separation Minimum) certification.

==== Regulatory Standards ====
Avionics installation is governed by strict regulatory frameworks to ensure the safety and reliability of aircraft systems. In the United States, the Federal Aviation Administration (FAA) sets the standards for avionics installations. These include guidelines for:
* '''System Performance''': Avionics systems must meet performance benchmarks as defined by the FAA, ensuring they function correctly in all phases of flight.
* '''Certification''': Shops performing installations must be FAA-certified, and their technicians often hold certifications such as the General Radiotelephone Operator License (GROL).
* '''Inspections''': Aircraft equipped with newly installed avionics systems must undergo rigorous inspections before being cleared for flight, including both ground and flight tests.

==== Advancements in Avionics Technology ====
The field of avionics has seen rapid technological advancements in recent years, leading to more integrated and automated systems. Key trends include:
* '''Glass Cockpits''': Traditional analog gauges are being replaced by fully integrated glass cockpit displays, providing pilots with a centralized view of all flight parameters.
* '''NextGen Technologies''': ADS-B and satellite-based navigation are part of the FAA's NextGen initiative, aimed at modernizing air traffic control and improving the efficiency of the national airspace.
* '''Autonomous Systems''': Advanced automation systems are paving the way for more autonomous aircraft systems, enhancing safety, efficiency, and reducing pilot workload.

===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]] of 118.000&nbsp;MHz to 136.975&nbsp;MHz. Each channel is spaced from the adjacent ones by 8.33&nbsp;kHz in Europe, 25&nbsp;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 communication|simplex]] mode. Aircraft communication can also take place using HF (especially for trans-oceanic flights) or satellite communication.

{{See also|Aircraft Communication Addressing and Reporting System}}

===Navigation===

{{Main|Air 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]] and [[WAAS]]), [[inertial navigation system]] (INS), ground-based [[radio navigation]] systems (such as [[VHF omnidirectional range|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===

{{Main|Glass cockpit}}
[[File:Airbus A380 cockpit.jpg|thumb|The [[Airbus A380]] glass cockpit featuring pull-out keyboards and two wide computer screens on the sides for pilots]]

The first hints of [[glass cockpit]]s 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.<ref name="three">''Avionics: Development and Implementation'' by Cary R. Spitzer (Hardcover – December 15, 2006)</ref>
Glass cockpits started to come into being with the [[Gulfstream Aerospace|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.<ref name="three"/>

===Aircraft flight-control system===

{{Main|Aircraft flight control system}}
Aircraft have means of automatically controlling flight. [[Autopilot]] was first invented by [[Lawrence Sperry]] during [[World War&nbsp;I]] to fly bomber planes steady enough to hit accurate targets from 25,000 feet. When it was first adopted by the [[U.S.&nbsp;military]], a [[Honeywell Aerospace|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.<ref name="two">By Jeffrey L. Rodengen. {{ISBN|0-945903-25-1}}. Published by Write Stuff Syndicate, Inc. in 1995. "The Legend of Honeywell."</ref>

The first simple commercial auto-pilots were used to control [[Aircraft heading|heading]] and altitude and had limited authority on things like [[thrust]] and [[flight control]] surfaces. In [[helicopter]]s, auto-stabilization was used in a similar way. The first systems were electromechanical. The advent of [[fly-by-wire]] 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 alleviate wing 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===

{{Main|Aircraft collision avoidance systems}}
To supplement [[air traffic control]], most large transport aircraft and many smaller ones use a [[TCAS|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]]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 [[GPWS|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===
{{Main|Flight recorder}}

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===
{{Main|Weather radar|Lightning detector}}
Weather systems such as [[weather radar]] (typically [[Arinc&nbsp;708]] on commercial aircraft) and [[lightning detector]]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 [[Clear-air turbulence|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]]) 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]] and turbulence detection and terrain and traffic warning systems.<ref name="four">{{cite news
 | last =Ramsey
 | first =James
 | title =Broadening Weather Radar's Scope
 | publisher =Aviation Today
 | date =August 1, 2000
 | url =http://www.aviationtoday.com/av/commercial/Broadening-Weather-Radars-Scope_12786.html
 | access-date =January 25, 2012
 | archive-date =January 18, 2013
 | archive-url =https://web.archive.org/web/20130118175850/http://www.aviationtoday.com/av/commercial/Broadening-Weather-Radars-Scope_12786.html
 | url-status =live
 }}</ref> In‑plane weather avionics are especially popular in [[Africa]], [[India]], and other countries where air-travel is a growing market, but ground support is not as well developed.<ref>{{cite news
 | last =Fitzsimons
 | first =Bernard
 | title =Honeywell Looks East While Innovating For Safe Growth
 | publisher =Aviation International News
 | date =November 13, 2011
 | url =http://www.ainonline.com/?q=aviation-news/dubai-air-show/2011-11-13/honeywell-looks-east-while-innovating-safe-growth
 | access-date =December 27, 2011
 | archive-date =November 16, 2011
 | archive-url =https://web.archive.org/web/20111116164353/http://www.ainonline.com/?q=aviation-news%2Fdubai-air-show%2F2011-11-13%2Fhoneywell-looks-east-while-innovating-safe-growth
 | url-status =live
 }}</ref>

===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]]s and the latest generation of [[airliner]]s.