Which of the following are the four forces of flight affecting an aircraft?

The correct answer identifies the four forces of flight as lift, weight, thrust, and drag.

Lift is the force that acts perpendicular to the direction of the airflow around the aircraft and allows it to rise and remain airborne. Weight is the force caused by gravity pulling the aircraft toward the Earth, and it counteracts lift. Thrust is the forward force produced by the aircraft's engines, propelling it through the air, while drag acts against this motion, opposing thrust and slowing the aircraft down. Together, these four forces are essential for understanding how an aircraft maneuvers in the sky and how pilots manage stability and control during flight.

Other options include incorrect components. For instance, altitude is not a force but rather a measurement of height above a reference level, commonly the Earth's surface. Speed, while important for flight dynamics, is also not classified as one of the four forces. Lastly, aerodynamic pressure, although a factor in the generation of lift and drag, does not constitute one of the primary forces of flight. Hence, focusing on the correct classification of lift, weight, thrust, and drag is essential in aerodynamics.