What is the primary purpose of fins on the AIM-120's control section?

• A. To measure airspeed
• B. To steer the missile in flight
• C. To house sensors
• D. To deploy parachute

Answer: (B)

Fins on the AIM-120’s control section are movable aerodynamic surfaces that the guidance system uses to steer the missile. When the onboard computer issues steering commands, the fins deflect to create the necessary yaw and pitch forces, changing the missile’s flight path so it can intercept the target. This is how the missile maintains stability and accurately reaches the desired trajectory at high speeds.

A airspeed is measured by dedicated air-data sensors like pitot tubes, not by the fins. The fins don’t house sensors either—the sensors are in other parts of the missile. Deploying a parachute isn’t part of its standard interception sequence.