Avionics is a term used to describe all of the electronic systems used on aircraft, artificial satellites and spacecraft. Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles. These can be as simple as a searchlight for a police helicopter or as complicated as the tactical system for an airborne early warning platform.
The term avionics is believed to have been coined by journalist Philip J. Klass. Avionics was pioneered in the 1970s, driven by military need rather than civil airliner development. Military aircraft had become flying sensor platforms, and making large amounts of electronic equipment work together had become the new challenge. Today, avionics as used in military aircraft almost always forms the biggest part of any development budget. Aircraft like the F-15E and the now retired F-14 have roughly 80 percent of their budget spent on avionics. Most modern helicopters 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) 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.
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 Honeywell (which now owns Bendix/King), Rockwell Collins, Thales Group, Garmin and Avidyne Corporation.
International standards for avionics equipment are prepared by the Airlines Electronic Engineering Committee (AEEC) and published by ARINC.
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 MHz to 136.975 MHz. Each channel is spaced from the adjacent ones by 8.33 kHz. 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.
See also: Aircraft Communication Addressing and Reporting System
Main article: Radio navigation
Navigation is the determination of position and direction on or above the surface of the Earth. Avionics can use satellite-based systems (such as GPS and WAAS), ground-based systems (such as VOR or LORAN), or any combination thereof. Navigation systems calculate the position automatically and display it to the flight crew on moving map displays.
Main article: Glass cockpit
Glass cockpits started to come into being with the Boeing 767 in 1982 and the Gulfstream G-IV private jet in 1985. Display systems provide sensor data that allows the aircraft to fly safely. Much information that previously was displayed on mechanical gauges now appears on electronic displays in newer aircraft.
Aircraft flight control systems
Main article: Aircraft flight control systems
Aircraft have means of automatically controlling flight. They reduce...
Please join StudyMode to read the full document