Question

If climb gradient is G, then which of the following is correct?

(a) T/W ≥ G + 2*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\)

(b) T/W ≥ G + 4*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\)

(c) T/W ≥ G – 2*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\)

(d) T/W ≥ G – 4*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\)

This question was posed to me in a job interview.

Asked question is from Selection of Thrust-Weight and Wing Loading in section Thrust-Weight Ratio and Wing Loading of Aircraft Design

Answer 1

The correct option is (a) T/W ≥ G + 2*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\)

Best explanation: Climb gradient is defined as the ratio between vertical distance and horizontal distance travelled during climb. For positive wing loading, thrust loading should follow following condition. T/W ≥ G + 2*\(\sqrt{\frac{CD0}{ᴨ*e*AR}}\).