Which factor primarily affects the maximum weight an aircraft can carry?

The maximum weight an aircraft can carry is primarily influenced by the flight envelope. The flight envelope defines the limits of operation for an aircraft, encompassing the speed, altitude, and load factors it can safely handle. Within this envelope, there are specific parameters that dictate how much weight the aircraft can safely operate with, including structural limits and aerodynamic capabilities.

The flight envelope is critical because it ensures that the aircraft remains within safe operating limits during various phases of flight, such as takeoff, cruising, and landing. If an aircraft exceeds its maximum weight, it can lead to performance issues such as increased takeoff distance, reduced climb rate, and potential instability, which can compromise safety.

While wing area, engine power, and center of gravity also play essential roles in aircraft performance, they are secondary to the overarching constraints defined by the flight envelope. Wing area affects lift generation, engine power influences thrust, and center of gravity impacts stability, but none of these can change the fundamental limits set by the flight envelope regarding maximum weight capacity.