Definition
The lowest total drag an airplane produces in flight, occurring at a specific airspeed where induced drag (from generating lift) and parasite drag (from pushing through the air) are equal. This airspeed corresponds to the airplane's best lift-to-drag ratio (L/D max) and is the most aerodynamically efficient speed for that airplane.
Plain English
The speed at which the airplane has the least total resistance in the air. Fly slower or faster than this speed and drag goes up.
Context Anchor
Seen in takeoff and climb performance discussions, especially when judging how the airplane accelerates after liftoff during a short-field takeoff.
Derivation
Minimum comes from the Latin minimus, meaning smallest. Drag is the resisting pull or force that slows something moving through a fluid, such as air. Together, minimum drag means the smallest amount of air resistance acting on the airplane.
Why Pilots Care
This speed gives the steepest climb angle after liftoff, helping clear obstacles on a short runway.
Grounding Statement
Picture the airplane just after liftoff: if it is too slow or held at too high a nose-up attitude, resistance increases; minimum drag is the low-resistance point between those extremes.
Intuition Check
Minimum drag does not mean no drag. It means the lowest total drag available for that airplane in that condition, and it is not automatically the same thing as the safest takeoff speed.
Example Sentence 1
After losing engine power, the pilot pitched for best glide speed, which corresponds to the minimum drag airspeed for that airplane.
Example Sentence 2
The handbook notes that best angle of climb is achieved near minimum drag speed.