Definition
Vertical air movement experienced in flight, where 'sinking' is a downward motion of the air mass carrying the airplane down with it, and 'lifting' is an upward motion of the air mass carrying the airplane up with it. These movements are caused by uneven heating of the surface, terrain features, frontal activity, or convective currents, and they cause the airplane to gain or lose altitude even when pitch and power are unchanged.
Plain English
The air itself is going up or down, and the airplane goes with it. If the air is sinking, the airplane drifts down. If the air is lifting, the airplane drifts up. The pilot didn't do anything different — the air moved.
Context Anchor
Common in weather discussions about wind near terrain, turbulence, thermals, and approach or landing conditions.
Why Pilots Care
Unanticipated sinking or lifting can cause rapid altitude loss near terrain or sudden airspeed changes that demand immediate correction.
Grounding Statement
Picture flying through an invisible patch of air that is moving downward or upward, carrying the airplane with it for a short time.
Intuition Check
Do not assume “sinking and lifting” means the pilot is intentionally descending or climbing. Here it means the air mass is moving vertically, and the airplane responds as it passes through that air.
Example Sentence 1
On short final, the pilot felt the airplane sinking and added power to maintain the glidepath.
Example Sentence 2
In the lee of the mountains sinking air produced a sudden descent that required immediate forward pressure and power.