Definition
The forces produced on an aircraft by its motion through the air. The four primary aerodynamic forces are lift (acting upward, perpendicular to the relative wind), drag (acting rearward, opposing motion), thrust (acting forward, produced by the powerplant), and weight (acting downward due to gravity). In steady flight these forces are in balance; any change in airspeed, attitude, or configuration alters them and changes the aircraft's flight path.
Plain English
The pushing and pulling forces the air creates on an aircraft as it moves. They are what make it climb, descend, speed up, slow down, or stay level.
Context Anchor
In the Vertical Speed Indicator discussion, this term helps explain that the airplane’s actual climb or descent comes from how the air is acting on the aircraft, while the VSI shows the resulting vertical motion with some delay.
Derivation
From Greek aer (air) and dynamis (power or force). Aerodynamic literally means 'the power of moving air.' The term captures the idea that these forces only exist when air and aircraft are in motion relative to each other.
Why Pilots Care
Balance among these forces keeps the aircraft stable; any imbalance changes altitude or speed and shows immediately on the VSI.
Grounding Statement
Picture the aircraft moving through air: the air is not empty space to the airplane; it presses, pulls, and resists as the airplane moves through it.
Intuition Check
Aerodynamic forces are not engine power by itself, and they are not gravity by itself. They are the forces caused by air flowing around the aircraft.
Example Sentence 1
When the pilot lowered the flaps, the aerodynamic forces shifted, producing more lift and more drag at the same airspeed.
Example Sentence 2
Extending flaps increases drag, upsetting the balance of aerodynamic forces and causing the VSI to indicate a descent.