The force that results from the acceleration due to gravity, always acts toward the center of the earth opposing lift. What is this force called?

• A. Drag
• B. Lift
• C. Weight
• D. Thrust

Answer: (C)

Weight is the force produced by gravity acting on the aircraft’s mass, pulling toward the center of the Earth. It points downward and is the force that lift must counter in steady level flight. Its magnitude is W = m × g and can vary with altitude and location because gravity isn’t perfectly constant. In flight, lift acts upward to balance weight, while thrust pushes forward and drag resists that forward motion. Since weight acts vertically downward regardless of the airplane’s attitude, it is the gravity-driven force that lift opposes to maintain altitude.