The center of lift tends to move forward with an increase in angle of attack and move aft with a decrease in angle of attack. This statement is:

• A. False
• B. It depends on the configuration
• C. True
• D. Not determinable from the data

Answer: (C)

The center of lift (center of pressure) is determined by how the pressure distribution over the wing shifts as the angle of attack changes. When you increase the angle of attack, the pressure pattern on the wing shifts so that the resultant lift force is more forward along the chord—toward the leading edge. Conversely, when you decrease the angle of attack, the pressure distribution moves in the opposite way, and the resultant lift moves aft, toward the trailing edge. This is a common behavior in subsonic, attached-flow conditions, while near stall the exact position can become less predictable as flow separation occurs. The aerodynamic center stays roughly fixed near the quarter-chord, but the center of lift slides forward with higher angles and aft with lower angles, matching the statement.