The primary purpose of the speed brake is to decelerate and/or increase your descent rate without increasing your airspeed.

• A. Flaps system
• B. Landing gear
• C. Speed brake
• D. Wheel brake

Answer: (C)

Speed brakes are dedicated drag devices that, when deployed, disrupt the airflow to create additional aerodynamic drag. That extra drag slows the airplane and lets you descend more steeply without letting airspeed rise. In other words, you can trim a controlled, steeper descent while keeping airspeed from increasing, or even reducing it, by using the speed brake.

Other options don’t serve this specific energy-management role. Flaps mainly increase lift at lower speeds to allow slower flight and takeoff/landing performance, not primarily to create drag for a controlled descent without speeding up. Landing gear and wheel brakes are related to ground operations or retraction in flight (wheel brakes work on the ground, and landing gear is largely retracted to reduce drag in flight). The speed brake is the tool designed to decelerate and deepen the descent without raising airspeed.