What are the four fundamental forces acting on an aircraft in flight?

The four fundamental forces acting on an aircraft in flight are lift, weight, thrust, and drag.

Lift is the upward force that counteracts the weight of the aircraft and is generated by the wings as air flows over them. The shape and angle of the wings (airfoil) significantly influence the amount of lift produced.

Weight is the force exerted by gravity acting downward on the aircraft. It depends on the mass of the aircraft and is a crucial factor to consider during flight since it must be balanced by lift for sustained flight.

Thrust is the forward force produced by the aircraft's engines, which propels it through the air. This force must overcome drag for the aircraft to accelerate.

Drag, the aerodynamic resistance an aircraft experiences as it moves through the air, acts opposite to thrust. It arises from the friction of air particles against the aircraft's surfaces and must be minimized for efficient flight.

Understanding these four forces is essential for analyzing flight dynamics and aircraft performance.