Definition
A type of instrument display face that is oriented vertically on the panel, with the indicating numbers or markings shown on a flat or slightly curved card that the pilot reads head-on, like a clock face. On a heading indicator with a vertical dial, the compass card sits upright behind the glass and rotates to show the aircraft's current heading against a fixed lubber line at the top.
Plain English
A round instrument face that stands upright on the panel, so you read it straight on, the same way you read a wall clock.
Context Anchor
Seen in discussions of heading indicators, where the aircraft’s heading is shown on an upright instrument display in the cockpit panel.
Derivation
"Dial" comes from the Latin dies, meaning "day," originally referring to a sundial's marked face for telling time. The word came to mean any round, marked face used for reading a value. "Vertical" simply tells you the dial stands upright on the panel rather than lying flat.
Why Pilots Care
Knowing that the text is talking about the display face helps the pilot understand how the heading indicator presents direction, rather than confusing it with aircraft climb, descent, or vertical movement.
Analogy
Like the face of a wall clock you glance at across the room — upright, marked around the edge, read straight on.
Intuition Check
Do not read “vertical” here as meaning the airplane is moving up or down. Here it means the dial face is upright in the instrument panel.
Example Sentence 1
Most heading indicators use a vertical dial, so the pilot reads the current heading at the top of the instrument like the hands of a clock.
Example Sentence 2
During the instrument scan, the pilot cross-checked the vertical dial heading indicator against the magnetic compass to confirm the turn was complete.