Definition
The graduated markings on the face of an altimeter that show altitude in feet above a chosen reference, typically read by the position of the altimeter's pointers and digital drum against tick marks calibrated in hundreds and thousands of feet.
Plain English
The numbered markings on the altimeter dial that let you read your altitude. The needles or numbers line up with these marks to show how high you are.
Context Anchor
Seen on altimeter diagrams and on the face or screen of the aircraft altimeter during instrument reading.
Derivation
Altitude comes from a word meaning height. Indication means showing or pointing out. Scale, in this use, means an ordered set of marks for measuring something. Together, the phrase means the marked display that shows height.
Why Pilots Care
Provides the altitude readout used for terrain clearance, airspace compliance, and vertical navigation.
Analogy
It is like the numbered marks on a ruler. The marks do not create the measurement; they give you a clear way to read it.
Intuition Check
Do not read scale here as size or weight. In this term, scale means the numbered marks used to read altitude.
Example Sentence 1
During the climb, she cross-checked the altitude indication scale against the assigned altitude of 8,000 feet.
Example Sentence 2
During the preflight check, the altimeter's altitude indication scale was verified against the field elevation.