What is the relationship between the aircraft’s payload and its fuel efficiency?

The relationship between an aircraft's payload and its fuel efficiency centers around the concept of weight. When an aircraft carries a higher payload, it generally requires more energy to lift and maintain flight, which results in increased fuel consumption. This is due to the additional thrust needed to overcome the weight of the extra cargo or passengers, leading to the engines working harder and consuming more fuel over the same distance.

As payload increases, the aircraft's aerodynamic efficiency may also be affected, as heavier loads can influence the aircraft's speed and altitude capabilities. This, in turn, can lead to less optimal flight profiles and increased drag, further compounding fuel consumption issues.

In contrast, a lighter payload allows for smoother and more efficient flight operations, leading to less fuel burned per mile traveled. Therefore, the correct answer highlights this intrinsic relationship between weight and fuel consumption, reflecting standard principles in aviation regarding operational efficiency and performance.