Plain English Meaning

A two-in-one knob on the glass cockpit display that lets you open flight management pages, move a cursor around, and select or enter information. You turn the outer ring to jump between sections, turn the inner ring to scroll within a section, and push it in to start typing or to confirm a choice.

Full Definition

A dual concentric control knob on a Garmin G1000 (or similar) Primary Flight Display and Multi-Function Display used to access and manipulate the Flight Management System pages. The outer (large) knob typically moves between page groups or fields, the inner (small) knob moves within a group or changes a value, and pressing the knob usually activates the cursor for data entry or selection.

Context Anchor

Seen on glass-cockpit displays when using screen menus, including the nearest-airports on the primary flight display.