Definition
The rearward force exerted on an airplane by the air it is moving through, opposing the airplane's forward motion. In the context of landing gear, extending the gear into the airstream increases this force and helps slow the airplane.
Plain English
The pushing-back force the air creates against the airplane as it moves forward. Anything sticking out into the airflow, like the landing gear, adds to it.
Context Anchor
In the Airplane Flying Handbook landing gear section, you will see this idea when fixed or extended landing gear creates extra air resistance and affects airplane performance.
Derivation
From Greek 'aero' (air) and Latin 'dynamicus' (relating to force or motion). 'Drag' is plain English for something that pulls or holds back. Together: a force from the air that holds the airplane back.
Why Pilots Care
Higher drag reduces speed, increases fuel use, and shortens glide distance, directly affecting decisions about gear extension and configuration changes.
Analogy
Like sticking your hand out of a moving car window — the faster the car, the harder the air pushes back on your hand.
Grounding Statement
You can picture aerodynamic drag by holding your hand out of a moving car window and feeling the air push it backward.
Intuition Check
Drag does not mean something is physically dragging on the ground here. It means the air is resisting the airplane’s movement through it.
Example Sentence 1
Lowering the landing gear increased aerodynamic drag, which helped the pilot slow to approach speed without reducing power further.
Example Sentence 2
Pilots retract the gear after takeoff to reduce aerodynamic drag and improve climb performance.