Plain English Meaning

A simple autopilot mode that keeps the wings flat so the airplane does not roll left or right on its own. The pilot still controls direction; the autopilot just stops the airplane from tipping into a turn.

Full Definition

An autopilot function that automatically holds the aircraft's wings level by sensing roll deviations and applying corrective aileron input to keep the bank angle at zero degrees. It is the most basic form of lateral autopilot control and is often the only roll function provided by single-axis autopilots.

Context Anchor

Seen in autopilot system discussions, especially when describing basic roll modes or what the autopilot does when no or is selected.