Definition
The technique of controlling an airplane's attitude — its pitch and bank relative to the horizon — by reference to the flight instruments rather than by looking outside, and using those instrument indications to maintain or change the desired flight path.
Plain English
Flying the airplane purely by what the instruments tell you. Instead of judging the airplane's position by looking out the window, you read the instruments to know where the nose is pointed and how the wings are tilted, and you use the controls to keep or adjust that picture.
Context Anchor
Seen at the beginning of instrument training, especially in discussions of flying in clouds, haze, darkness, or any condition where the natural horizon is hard to see.
Derivation
Attitude here comes from the older meaning of 'posture' or 'position' — the way something is held in space. In aviation it refers to the airplane's posture relative to the horizon: nose up or down, wings level or banked.
Why Pilots Care
Prevents loss of control and spatial disorientation when flying in clouds or at night.
Grounding Statement
Picture flying into a cloud: the outside horizon disappears, so the instruments become the reference for keeping the airplane where you want it.
Intuition Check
Do not read “attitude” as mood or behavior here. In this term, attitude means the airplane’s nose-up, nose-down, and bank position compared with the horizon.
Example Sentence 1
On entering the cloud, the pilot transitioned to airplane attitude instrument flying, holding wings level and a slight nose-up pitch on the attitude indicator.
Example Sentence 2
Airplane attitude instrument flying becomes essential the moment visual references disappear in clouds.