The drag curve is produced by plotting which of the following?

• A. Lift coefficient versus rebuild factor
• B. Drag coefficient versus Reynolds number
• C. Velocity versus drag
• D. Induced drag and parasite drag

Answer: (D)

The drag curve reflects how drag changes with speed (or lift) and is formed by the sum of the two main drag components: induced drag and parasite drag. Induced drag arises from generating lift and decreases as speed increases, while parasite drag comes from the airframe’s shape, surface texture, and added equipment and generally grows with speed. When you plot total drag, you’re effectively plotting these two pieces together: at low speeds induced drag is dominant and drag is higher; as speed rises, induced drag falls and total drag reaches a minimum; at even higher speeds, parasite drag dominates and total drag climbs again. So the drag curve is produced by plotting the combination of induced drag and parasite drag.