Definition
An instrument that backs up the primary pitch instrument by showing the result of pitch attitude on the aircraft's performance, used to confirm and refine the pitch picture set on the attitude indicator. In straight-and-level flight, the supporting pitch instruments typically include the altimeter, vertical speed indicator, and airspeed indicator, which together verify that the selected pitch attitude is producing level flight.
Plain English
An instrument the pilot cross-checks to confirm that the pitch attitude they have set is actually doing what they want — for example, holding altitude.
Context Anchor
Seen in instrument scan discussions, especially in figures that show which instruments are primary and which are supporting during straight-and-level flight.
Derivation
Supporting' comes from the Latin supportare, meaning 'to carry' or 'to bear up.' In this context, the supporting instruments 'hold up' the pilot's pitch control by confirming what the primary instrument is showing.
Why Pilots Care
Enables precise altitude and attitude control plus quick detection of pitch deviations when the attitude indicator is in use.
Intuition Check
Do not read “supporting” as “less important.” It means the instrument is used to confirm or back up the main pitch reference. Do not read “pitch” as sound or throwing. Here it means the airplane’s nose-up or nose-down position.
Example Sentence 1
While holding altitude, the pilot used the attitude indicator as the primary pitch instrument and scanned the altimeter and VSI as supporting pitch instruments to confirm level flight.
Example Sentence 2
After a power reduction, the vertical speed indicator serves as a supporting pitch instrument to confirm the nose attitude.