The four forces acting on an RPAS are:

The four forces acting on an RPAS are:

• A. Lift, Drag, Torque and Thrust
• B. Lift, Weight, Thrust and Drag
• C. Torque, Weight, Thrust and Drag
• D. Lift, Torque, Thrust and Drag

Answer: (B)

The four fundamental forces acting on a remotely piloted aircraft system (RPAS) are lift, weight, thrust, and drag. These forces play critical roles in the flight dynamics of the aircraft. Lift is the upward force that allows the aircraft to rise off the ground. It is generated primarily by the wings as air flows over and beneath them. Weight is the downward force due to gravity acting on the mass of the aircraft, which must be countered by lift for the RPAS to maintain altitude or ascend. Thrust is the forward force produced by the aircraft's propulsion system, which propels the RPAS through the air. It must overcome drag, which is the aerodynamic resistance that opposes the motion of the aircraft as it moves through the air. Together, these four forces govern the flight characteristics and performance of the RPAS, and they must be balanced correctly for safe and controlled flight. The other choices include forces that do not accurately describe the main flight dynamics: torque refers to the rotational force that can affect the aircraft’s stability but is not one of the primary forces that must be balanced in straight and level flight.

The four fundamental forces acting on a remotely piloted aircraft system (RPAS) are lift, weight, thrust, and drag. These forces play critical roles in the flight dynamics of the aircraft.

Lift is the upward force that allows the aircraft to rise off the ground. It is generated primarily by the wings as air flows over and beneath them. Weight is the downward force due to gravity acting on the mass of the aircraft, which must be countered by lift for the RPAS to maintain altitude or ascend.

Thrust is the forward force produced by the aircraft's propulsion system, which propels the RPAS through the air. It must overcome drag, which is the aerodynamic resistance that opposes the motion of the aircraft as it moves through the air. Together, these four forces govern the flight characteristics and performance of the RPAS, and they must be balanced correctly for safe and controlled flight.

The other choices include forces that do not accurately describe the main flight dynamics: torque refers to the rotational force that can affect the aircraft’s stability but is not one of the primary forces that must be balanced in straight and level flight.