Which of the following is NOT a major component of fixed-wing aircraft structure?

The helicopter rotor is not a component of fixed-wing aircraft structure. Fixed-wing aircraft primarily rely on a rigid airfoil structure to generate lift, which is achieved through wings—elements that differ significantly from the rotor systems used in helicopters.

Fuselage, tail assembly, and landing gear are all integral parts of fixed-wing aircraft. The fuselage is the main body of the airplane that houses passengers, cargo, and the cockpit. The tail assembly, often composed of stabilizers and a rudder, is crucial for aerodynamic stability and control during flight. The landing gear supports the aircraft during takeoff and landing and includes wheels or other mechanisms necessary for ground operations. Understanding these components helps differentiate between fixed-wing and rotary-wing aircraft systems.