Modern aircraft are flying computers. Avionics covers the electronic systems that handle navigation, communication, flight control, weather radar, and engine monitoring. On a new airliner, avionics account for a large share of the total cost.

The field grew as vacuum tubes and mechanical gyros gave way to solid-state electronics. Digital buses now connect dozens of line-replaceable units, each handling a specific function and each designed for quick swap on the ramp.

Key avionics systems

• Flight management computers
• Inertial and satellite navigation
• Radio and data link communication
• Weather radar and traffic awareness
• Fly-by-wire control computers

Redundancy is built into everything. Triple or quadruple channels compare outputs and vote out a faulty unit. A single failure should never compromise the flight.