A force applied to an aircraft that causes bending of the aircraft structure and doesn't return to its original shape describes which load?

A force applied to an aircraft that causes bending of the aircraft structure and doesn't return to its original shape describes which load?

• A. Limit Load
• B. Ultimate Load
• C. Factor of Safety
• D. Overloading

Answer: (A)

When a load bends an aircraft structure, the material initially deforms elastically, so it returns to its original shape when the load is removed. As the load increases beyond this elastic range, permanent (plastic) deformation begins and the structure won’t revert to its original shape. In design terms, the limit load is the greatest load the structure is intended to endure without accumulating permanent deformation; beyond this, non-recoverable bending occurs as you move toward the ultimate load and possible failure. So the scenario described—bending that does not recover after unloading—fits the limit load concept: it marks the boundary where deformation becomes irreversible, and it’s the closest match among the given options. The ultimate load is the point of failure, the factor of safety is the margin used in design, and overloading is simply applying more load than the design allows.

When a load bends an aircraft structure, the material initially deforms elastically, so it returns to its original shape when the load is removed. As the load increases beyond this elastic range, permanent (plastic) deformation begins and the structure won’t revert to its original shape. In design terms, the limit load is the greatest load the structure is intended to endure without accumulating permanent deformation; beyond this, non-recoverable bending occurs as you move toward the ultimate load and possible failure.

So the scenario described—bending that does not recover after unloading—fits the limit load concept: it marks the boundary where deformation becomes irreversible, and it’s the closest match among the given options. The ultimate load is the point of failure, the factor of safety is the margin used in design, and overloading is simply applying more load than the design allows.