What type of drag increases with decreasing air density?

What type of drag increases with decreasing air density?

• A. Induced drag
• B. Wave drag
• C. Skin friction drag
• D. Form drag

Answer: (A)

Induced drag is a type of drag that primarily occurs due to the generation of lift. It is influenced by the lift being produced by the aircraft's wings and is directly related to the angle of attack and air density. As air density decreases, such as at higher altitudes, the aircraft needs to operate at a higher angle of attack to maintain the same lift. This increased angle of attack leads to an increase in induced drag. The relationship between lift and induced drag means that when air density is lower, the induced drag increases because more lift must be generated to counteract the decrease in density. Understandably, other forms of drag do not vary in the same manner with changes in air density. Skin friction drag, for instance, relates primarily to the surface area of the aircraft and the viscosity of the air; it does not inherently increase in direct correlation with air density changes. Form drag is influenced more by the shape of the aircraft and airflow separation rather than air density, while wave drag is associated with transonic and supersonic speeds, which again does not have a direct relationship with air density in the same context as induced drag.

Induced drag is a type of drag that primarily occurs due to the generation of lift. It is influenced by the lift being produced by the aircraft's wings and is directly related to the angle of attack and air density. As air density decreases, such as at higher altitudes, the aircraft needs to operate at a higher angle of attack to maintain the same lift. This increased angle of attack leads to an increase in induced drag. The relationship between lift and induced drag means that when air density is lower, the induced drag increases because more lift must be generated to counteract the decrease in density.

Understandably, other forms of drag do not vary in the same manner with changes in air density. Skin friction drag, for instance, relates primarily to the surface area of the aircraft and the viscosity of the air; it does not inherently increase in direct correlation with air density changes. Form drag is influenced more by the shape of the aircraft and airflow separation rather than air density, while wave drag is associated with transonic and supersonic speeds, which again does not have a direct relationship with air density in the same context as induced drag.