Definition
The aerodynamic effects produced by air flowing past and around an airplane in flight, including lift, drag, and the pressure forces acting on the wings, control surfaces, and airframe. During approach and landing, these forces influence how the airplane responds to control inputs, how it slows down, and how it settles onto the runway as airspeed decreases.
Plain English
The push and pull that moving air creates on the airplane as it flies through it. As the airplane slows down on approach, this push and pull weakens, which is why controls feel less responsive close to touchdown.
Context Anchor
Seen during approach and landing, especially when the airplane is slowing down and the pilot is judging how much control response remains during the roundout and flare.
Derivation
Airstream combines air with stream, an Old English term for a flowing current. In aviation the phrase emphasizes the directed flow past the moving airplane rather than random wind.
Why Pilots Care
These forces directly determine whether the airplane floats, sinks, or touches down smoothly; mismanaging them is a common cause of hard or bounced landings.
Analogy
It is like holding your hand out of a moving car window. At higher speed, the air pushes hard on your hand; at lower speed, the push is much weaker.
Grounding Statement
On final approach, the airplane is still moving through the air, and that moving air is what gives the wings and controls their working force.
Intuition Check
Do not think of the airstream as only natural wind blowing across the runway. In this context, it means the airflow the airplane meets as it moves, even on a calm day.
Example Sentence 1
As the airplane decelerated in the flare, the forces of the airstream diminished and the controls felt softer in his hands.
Example Sentence 2
A headwind increases the forces of the airstream at any given groundspeed, so the pilot must adjust pitch and power to maintain the correct descent path.