Definition
A force acting toward the ground on an aircraft or one of its surfaces. In the context of icing on airfoils, it refers to the increased downward pull caused by the added weight of accumulated ice and the disruption of lift, which together push the aircraft downward and increase the load the wings must support.
Plain English
A push or pull that drives something toward the ground. When ice builds up on a wing, the extra weight and loss of lift combine to pull the airplane down harder than normal.
Context Anchor
Seen in discussions of how ice changes the way the wing or tail handles airflow, especially when ice reduces the tail’s normal downward push.
Why Pilots Care
This force reduces climb capability, increases descent rate, and can contribute to loss of control if the pilot does not reduce angle of attack or exit the icing environment.
Grounding Statement
Picture the tail needing a steady downward push to help hold the airplane in balance; ice can weaken that push.
Intuition Check
Do not assume downward force means the whole airplane is descending. Here it usually means a downward push on a surface, especially the tail, while the airplane may still be flying level.
Example Sentence 1
As ice built up on the wings, the increasing downward force required the pilot to add power and raise the nose to hold altitude.
Example Sentence 2
The pilot noticed the airplane settling even with full power because the iced airfoil was generating a downward force rather than lift.