Total drag is defined as the sum of which components?

Total drag is defined as the sum of which components?

• A. Induced drag, profile drag, and parasite drag
• B. Induced drag, parasite drag, and skin-friction drag
• C. Profile drag, parasite drag, and form drag
• D. Lift, weight, and thrust

Answer: (A)

Total drag consists of two broad parts: drag from lift and drag that arises regardless of lift. The lift-related portion is induced drag, which appears because the wing creates lift by redirecting airflow downward; it tends to grow as you try to generate more lift (lower speeds or higher angles of attack) and diminishes as speed increases. The other portion is parasite drag, the drag that exists without contributing to lift. This comes from the aircraft’s shape and surface, including friction between the air and the skin (skin-friction or profile drag) and the pressure differences around the aircraft (form drag). In many treatments, profile drag is the portion of parasite drag tied to the aircraft’s profile and surface interactions, while parasite drag may be discussed as the broader category including form drag as well. So, total drag can be viewed as the sum of the lift-related drag and the non-lift-related drag, with the non-lift drag often broken down into profile drag and other parasite components. This is why listing induced drag, profile drag, and parasite drag together captures all the drag contributions at a given operating condition. Remember, lift, weight, and thrust are forces, not drag components.

Total drag consists of two broad parts: drag from lift and drag that arises regardless of lift. The lift-related portion is induced drag, which appears because the wing creates lift by redirecting airflow downward; it tends to grow as you try to generate more lift (lower speeds or higher angles of attack) and diminishes as speed increases.

The other portion is parasite drag, the drag that exists without contributing to lift. This comes from the aircraft’s shape and surface, including friction between the air and the skin (skin-friction or profile drag) and the pressure differences around the aircraft (form drag). In many treatments, profile drag is the portion of parasite drag tied to the aircraft’s profile and surface interactions, while parasite drag may be discussed as the broader category including form drag as well.

So, total drag can be viewed as the sum of the lift-related drag and the non-lift-related drag, with the non-lift drag often broken down into profile drag and other parasite components. This is why listing induced drag, profile drag, and parasite drag together captures all the drag contributions at a given operating condition. Remember, lift, weight, and thrust are forces, not drag components.