Name the four fundamental aerodynamic forces acting on an airplane in steady flight.

• A. Lift, ballast, thrust, and drag.
• B. Drag, weight, thrust, and lift.
• C. Lift, weight, thrust, and drag.
• D. Lift, weight, thrust, and lift.

Answer: (C)

The main idea is that in steady flight there are four aerodynamic forces: lift, weight, thrust, and drag. Lift acts upward to counteract weight, which pulls downward due to gravity. Thrust pushes the aircraft forward to overcome drag, which acts backward against the motion. When the aircraft isn’t accelerating, these forces balance each other so the net force is zero.

Lift, weight, thrust, and drag is the standard way to name them and the order aligns with how they’re typically presented in flight training. One option mentions ballast, which isn’t an aerodynamic force; another lists the four forces but in a nonstandard order; another repeats lift, which isn’t correct because weight, thrust, and drag are distinct forces.