The ZFW limitation is intended to limit which of the following?

• A. Wing loading limits in flight
• B. Wing structure limits in the air
• C. Center of gravity excursion
• D. Maximum fuel weight

Answer: (B)

The main idea being tested is how payload interacts with the aircraft’s structural limits in flight. The zero fuel weight limit is set to ensure that, when fuel is later added to reach the planned takeoff weight, the loads on the wings (and the airframe) remain within what the wing structure was designed to carry. If you carry payload up to the ZFW limit and then fill fuel to reach takeoff weight, the combination of heavy weight and its distribution can produce bending moments the wing isn’t designed to handle. Staying under the ZFW limit keeps the wing design margins intact across the flight envelope.

What this isn’t primarily about is wing loading in flight, which is a function of total weight per wing area rather than a single payload threshold. It also isn’t directly about CG excursion, though payload and fuel do affect CG; the ZFW limit’s purpose is to protect wing structure during flight. It’s not about maximum fuel weight either, since fuel is managed separately from the payload limit.