Avionics means "aviation electronics". It comprises electronic systems for use on aircraft, artificial satellites and spacecraft, comprising communications, navigation and the display and management of multiple systems. It also includes the hundreds of systems that are fitted to aircraft to meet individual roles, these can be as simple as a search light for a police helicopter or as complicated as the tactical system for an Airborne Early Warning platform.

History

The term avionics was not in general use until the early 1970s. Up to this point instruments, radios, radar, fuel systems, engine controls and radio navigation aids had formed individual (and often mechanical) systems.

In the 1970s, avionics was born, 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. (F-22?)

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. With the continued refinement of precision miniature aerospace bearings, guidance and navigation systems of aircrafts have become more exact.

Aircraft avionics

The cockpit of an aircraft is a major location for avionic equipment, including control, monitoring, communication, navigation, weather, and anti-collision systems. The majority of aircraft drive their avionics using 14 or 28 volt DC electrical systems; however, large, more sophisticated aircraft (such as airliners or military combat aircraft) have AC systems operating at 400 Hz, rather than the more common 50 and 60 Hz of North American home electrical devices. There are several major vendors of flight avionics, including Honeywell (which now owns Bendix/King, Baker Electronics, Allied Signal, etc..]), Rockwell Collins, Thales Group, Garmin, Avidyne Corporation, and Narco Avionics.

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 MHz to 136.975 MHz. Each channel is spaced from the adjacent by 8.33 kHz. Amplitude Modulation (AM) is used. The conversation is performed by simplex mode. Aircraft communication can also take place using HF (especially for trans-oceanic flights) or satellite communication.