What are the four forces relevant to flight in aerodynamics?

The four forces relevant to flight in aerodynamics are thrust, lift, drag, and weight.

Thrust is the force that propels an aircraft forward and is generated by engines. Lift is the upward force that counters weight, created by the movement of air over the wings. Drag is the resistance force that opposes thrust, resulting from air friction and other factors as the aircraft moves through the atmosphere. Weight is the force due to gravity acting on the aircraft, pulling it downward.

These forces are integral to understanding how aircraft achieve and maintain flight. The balance and interaction among these forces determine an aircraft's flight dynamics, stability, and performance. Recognizing these four fundamental forces allows for a clearer comprehension of how flight mechanics operate in practice.