Definition
A secondary, independently powered attitude indicator that displays the aircraft's pitch and bank relative to the horizon, used as a backup if the primary attitude reference fails or loses power.
Plain English
A small backup horizon instrument that keeps working if the main one fails, so the pilot can still see whether the aircraft is climbing, descending, or banking.
Context Anchor
Seen in instrument-flying emergency procedures, especially during electrical problems or when operating on limited battery power.
Derivation
Standby comes from the nautical sense of being held in reserve, ready to take over. The instrument is on standby — it is always running, but the pilot only relies on it when the primary fails.
Why Pilots Care
It supplies the essential attitude reference needed to avoid spatial disorientation and maintain controlled flight in instrument conditions when the primary system fails.
Grounding Statement
When outside visual cues are poor, the standby attitude indicator can be the backup picture of which way is up.
Intuition Check
Do not read attitude as emotional state here. In this term, attitude means the aircraft’s nose and wing position relative to the horizon; standby means backup, not inactive or unimportant.
Example Sentence 1
When the primary attitude indicator failed in the clouds, the pilot transitioned to the standby attitude indicator and continued the approach.
Example Sentence 2
During the preflight check on battery power, the pilot confirmed the standby attitude indicator was operational.