Plain English Meaning

The thing the pilot looks at to tell whether the airplane's nose is pointed up, down, or level, and whether the wings are tilted or flat.

Full Definition

A fixed visual or instrument-based source the pilot uses to determine the airplane's pitch and bank in relation to the horizon. In visual flight, the natural horizon serves as the attitude reference; in instrument flight, the attitude indicator (or equivalent instruments) replaces it.

Context Anchor

Seen in instrument flying when the outside horizon may not be visible, so the pilot needs a dependable way to judge the airplane’s position.

Derivation

From '' (the airplane's in space — its pitch and bank) and '' (something used as a fixed of comparison). Together: the fixed point used to judge how the airplane is oriented.