The center of lift is normally located aft of the center of gravity to balance the aircraft aerodynamically.

• A. False
• B. True
• C. Not determinable
• D. Depends on speed

Answer: (B)

Longitudinal stability relies on where the lift force effectively acts relative to the mass center. The center of lift (center of pressure) is the point where the wing’s resultant lift is considered to act, and its position relative to the center of gravity determines the pitching moment produced by a lift change or disturbance.

If the center of lift is aft of the center of gravity, the lift acts behind the mass center. An upward force applied behind the CG tends to rotate the aircraft’s nose down, which counteracts a disturbance that would raise the nose and increase the angle of attack. This creates a restoring, stabilizing moment, helping the aircraft return to its trimmed attitude.

In conventional airplanes, the geometry is such that this aft location of the lift relative to the CG contributes to stability, while the tailplane provides additional trim control to balance forces in steady flight. It’s worth noting that other configurations, like canards, place the lifting surface forward of the CG, which changes the stability interaction.

So the statement reflects how, in typical configurations, having the center of lift behind the center of gravity supports aerodynamic balance and stability. The other options aren’t necessary here, as this arrangement is a general characteristic of stable, conventional designs.