Which of the following is necessary to maintain structural integrity in a cantilever design?

Maintaining the shape of the airframe is essential in a cantilever design because the structure relies on its geometric configuration to distribute loads effectively. In cantilever structures, the shape helps resist bending moments and shear forces, ensuring stability and integrity throughout the airframe. A well-maintained shape allows the structure to perform as intended under various loading conditions, reducing the risk of failure by ensuring the loads are managed through the components of the design effectively.

In contrast, using external support structures, incorporating additional weight for balance, or employing strong materials only in visible areas do not address the inherent design principles that support cantilevered structures. Instead, these approaches could introduce complexities or weaknesses that compromise the overall integrity of the design. Therefore, maintaining the correct shape is crucial for ensuring that the cantilever can handle stresses while preserving its functional performance.