What are the two natural forces acting on an aircraft?

The correct answer recognizes the two fundamental natural forces acting on an aircraft, which are gravity and drag.

Gravity is the force that pulls the aircraft down towards the Earth, creating a need for the aircraft to generate lift in order to ascend and remain airborne. This force is constant and affects all objects with mass, including an aircraft.

Drag, on the other hand, is the resistance that the aircraft experiences as it moves through the air. It acts opposite to the direction of the aircraft's motion and is influenced by factors such as the shape of the aircraft, speed, and the density of the air. In aerodynamics, understanding drag is essential for optimizing aircraft performance and fuel efficiency.

The interplay between gravity, which primarily affects the vertical forces on an aircraft, and drag, which contributes to the challenges of forward motion, is critical in the study of flight mechanics and ensures the aircraft can navigate safely in the airspace system.