Definition
The selectable operating functions of an autopilot system that determine which flight parameters the autopilot will control and how it will control them. Modes are typically grouped into lateral modes (controlling heading or track, such as HDG, NAV, LNAV, or APPR), vertical modes (controlling altitude or vertical path, such as ALT, VS, FLC, or VNAV), and approach modes (such as APPR or LOC/GS for ILS coupling). Each mode is armed or engaged by the pilot through the autopilot control panel, and the active mode is shown on the flight mode annunciator.
Plain English
The different jobs you can ask the autopilot to do — like 'hold this heading,' 'climb at this speed,' 'level off at this altitude,' or 'fly the approach.' You pick the mode, and the autopilot flies the airplane that way until you change it.
Context Anchor
Seen on the autopilot control panel, flight display, or mode display while using automation during instrument flight.
Derivation
Mode' comes from the Latin modus, meaning 'a way' or 'manner.' An autopilot mode is simply a way the autopilot is set up to fly the airplane at that moment.
Why Pilots Care
Selecting the correct mode lets the autopilot handle precise flight tasks, lowering workload and helping maintain accuracy during instrument procedures.
Grounding Statement
The key question is always: what is the autopilot doing right now, and what is it set up to do next?
Intuition Check
Do not assume “autopilot on” means the system is doing everything. The specific autopilot modes tell you exactly which parts of the flying it is controlling.
Example Sentence 1
After level-off, the pilot selected ALT mode for altitude hold and HDG mode to follow the assigned heading from ATC.
Example Sentence 2
After leveling off, she engaged altitude hold mode to keep the aircraft at the cleared flight level.