What do longerons provide in an aircraft's structure?

• A. Flexibility in the wings
• B. Control surfaces movement
• C. Rigidity and strength along the fuselage
• D. Suction for enhanced aerodynamic flow

Answer: (C)

Longerons are structural components that run longitudinally along the fuselage of an aircraft. Their primary function is to provide rigidity and strength to the aircraft's structure. By reinforcing the fuselage, longerons help distribute the loads and stresses experienced during flight, ensuring the aircraft can withstand various forces without deforming. This structural integrity is crucial for maintaining the aircraft's shape and safety during operation.

In contrast, flexibility in the wings is typically achieved through other design elements like wing spars and ribs, which are not directly related to the role of longerons. The movement of control surfaces, such as ailerons and elevators, is facilitated by different mechanisms like control cables or hydraulic systems, rather than the longerons. Lastly, while aerodynamic flow is vital for flight, suction effects relate to airflow over the wings and control surfaces, and not to the structural components like longerons. Therefore, the emphasis on the longerons' role in providing structural support highlights their importance in the overall integrity and performance of the aircraft.