How does heavier weight affect rate of climb and power required for a given climb?

How does heavier weight affect rate of climb and power required for a given climb?

• A. Heavier weight increases rate of climb and decreases power required.
• B. Heavier weight decreases rate of climb and increases power required.
• C. Heavier weight increases rate of climb and increases power required.
• D. Heavier weight has no effect on rate of climb or power required.

Answer: (B)

Heavier weight makes climb performance worse because it increases the lift needed, which raises drag, especially the induced drag from generating more lift. At a given airspeed, more thrust (power) is required to overcome this extra drag. Since the engine’s power output is effectively fixed, the amount of power left over to push the aircraft upward—the excess power—shrinks as weight increases. Rate of climb depends on that excess power relative to weight, so when weight goes up, the excess power is smaller and the rate of climb falls. In short, for a climb at a given speed, heavier weight means higher power required and a lower rate of climb.

Heavier weight makes climb performance worse because it increases the lift needed, which raises drag, especially the induced drag from generating more lift. At a given airspeed, more thrust (power) is required to overcome this extra drag. Since the engine’s power output is effectively fixed, the amount of power left over to push the aircraft upward—the excess power—shrinks as weight increases. Rate of climb depends on that excess power relative to weight, so when weight goes up, the excess power is smaller and the rate of climb falls. In short, for a climb at a given speed, heavier weight means higher power required and a lower rate of climb.