Lift on a wing is most properly defined as the force acting in which direction relative to the relative wind?

Lift on a wing is most properly defined as the force acting in which direction relative to the relative wind?

• A. Perpendicular to the relative wind
• B. Parallel to the relative wind
• C. Along the flight path
• D. Opposite to weight

Answer: (A)

Lift is the aerodynamic force that acts perpendicular to the relative wind. The relative wind is the air rushing past the wing as the aircraft moves, and lift arises from the pressure difference produced by that flow. This perpendicular orientation is what allows lift to support the aircraft’s weight, while other forces align differently—for example, drag acts parallel to the relative wind. In steady level flight, lift balances weight, but its direction remains perpendicular to the incoming air.

Lift is the aerodynamic force that acts perpendicular to the relative wind. The relative wind is the air rushing past the wing as the aircraft moves, and lift arises from the pressure difference produced by that flow. This perpendicular orientation is what allows lift to support the aircraft’s weight, while other forces align differently—for example, drag acts parallel to the relative wind. In steady level flight, lift balances weight, but its direction remains perpendicular to the incoming air.