Definition
The downward movement of air associated with convective downdrafts, typically found over cooler surfaces such as water, plowed fields, or shaded ground, where the air is denser and descends. An aircraft flying through this descending air experiences a loss of altitude unless corrected with pitch and power.
Plain English
Air over cooler ground sinks, and an airplane flying through that sinking air gets pushed downward.
Context Anchor
Seen in weather discussions about convective currents, especially near the ground during approach, landing, or flight over surfaces that heat unevenly.
Why Pilots Care
It can produce sudden loss of altitude or reduced climb performance, especially dangerous near terrain or during low-altitude operations.
Grounding Statement
Cool surfaces produce descending air; warm surfaces produce rising air. The sinking effect is the descending half of that pattern.
Intuition Check
Do not read “sinking effect” as the airplane simply descending normally. Here it means an unexpected settling caused by the movement of the air around the airplane.
Example Sentence 1
Crossing the lake on final, the pilot felt the sinking effect and added power to hold the glide path.
Example Sentence 2
Convective currents often produce rising air on one side of a ridge and a sinking effect on the other.