The total aerodynamic drag on an aircraft is a sum of which two types of drag?

The total aerodynamic drag on an aircraft is indeed the sum of induced drag and parasite drag. Induced drag is associated with the generation of lift; as an aircraft generates lift, it creates vortices that contribute to drag. This type of drag generally increases with an increase in angle of attack and decreases as speed increases.

On the other hand, parasite drag encompasses all forms of drag that are not related to lift generation. It includes components like form drag (related to the shape of the aircraft), skin friction drag (due to the friction of air molecules sliding over the surface), and interference drag (caused by the interaction of airflow over different parts of the aircraft). Parasite drag increases with an increase in speed and is significant at cruising speeds.

Together, these two forms of drag—induced and parasite—capture the full picture of the opposition to the aircraft's movement through the air, making the understanding of both critical in aerodynamic design and performance assessment.