Definition
Avionics equipment that uses ground-based navigation aids — such as VOR, DME, NDB, and ILS — to navigate, rather than satellite-based or area navigation (RNAV) systems. An aircraft equipped only with conventional avionics can fly procedures defined by ground stations but cannot fly RNAV or GPS-based routes and approaches.
Plain English
The older style of cockpit navigation gear that relies on signals from ground stations on the ground, not from satellites or computer-generated waypoints.
Context Anchor
Seen during instrument departure planning, especially when checking whether the airplane is equipped to fly a standard instrument departure as published.
Derivation
Conventional' comes from Latin conventio, meaning 'an agreed or established way.' In avionics, it refers to the long-established method of navigating by ground-based stations — the standard before GPS and RNAV became widespread.
Why Pilots Care
Pilots must recognize when an aircraft uses conventional avionics because it affects how navigation information is displayed and interpreted during instrument departures.
Intuition Check
Conventional does not mean casual, optional, or less precise here. It means navigation based on established ground-based radio signals, rather than a system that freely calculates point-to-point routes.
Example Sentence 1
Because the aircraft was limited to conventional avionics, the pilot selected a SID defined by VOR radials instead of an RNAV departure.
Example Sentence 2
Aircraft equipped with conventional avionics require more frequent instrument scans during departure compared to those with integrated displays.