With constant load factor, which statement is correct about induced drag when speed and mass change?

• A. 1 is true and 2 is true
• B. 1 is true and 2 is false
• C. 1 is false and 2 is true
• D. 1 is false and 2 is false

Answer: (B)

Induced drag comes from the need to generate lift, and at a given load factor the lift required is L = nW (n is the load factor, W is weight). Heavier weight means more lift is required, which increases induced drag, roughly with the square of the weight. On the other hand, increasing speed while holding the load factor constant lowers the angle of attack needed to produce that lift, so the lift coefficient rises less for the same weight, and induced drag decreases with speed (roughly proportional to 1/V^2 for fixed n).

So the statement that induced drag decreases with increasing speed at constant load factor is true, while the idea that induced drag is independent of mass (weight) is false. Heavier mass increases induced drag, all else equal.