Definition
The pitch attitude required to maintain level flight at a given airspeed and power setting, used as the reference pitch the pilot holds and returns to during straight-and-level instrument flight.
Plain English
The nose position that keeps the airplane flying level at the speed and power you have set. You hold this position, and if it shifts, you put it back.
Context Anchor
Seen in instrument flying when using the primary-and-supporting instrument method during straight-and-level flight and other basic instrument maneuvers.
Derivation
The word 'supporting' comes from the Latin 'supportare', meaning to carry or hold up. Here it describes the pitch attitude that holds the aircraft up at level flight — the pitch that supports level cruise.
Why Pilots Care
Correct supporting pitch prevents unintended climbs, descents, or airspeed changes and reduces pilot workload.
Grounding Statement
If you are trying to hold level flight and one instrument shows the airplane is starting to drift up or down, that instrument may be giving supporting pitch information.
Intuition Check
Do not read “supporting pitch” as holding the nose up physically, or as pitch in the sense of sound. Here, “pitch” means nose-up or nose-down attitude, and “supporting” means backing up the main instrument information.
Example Sentence 1
Once established at cruise power, the pilot noted the supporting pitch on the attitude indicator and held it to maintain altitude.
Example Sentence 2
If the airspeed begins to increase, the pilot raises the nose to the new supporting pitch to restore the desired performance.