What is the primary purpose of the speed brake?

The primary purpose of the speed brake is to decelerate and increase the descent rate without increasing airspeed. Speed brakes are devices used on various aircraft to reduce speed and increase drag, allowing the aircraft to descend more rapidly while maintaining a controlled airspeed. This is particularly useful during landing approaches, where a pilot may need to descent quickly without the risk of gaining too much airspeed.

The use of the speed brake allows for better control over the aircraft's descent profile, enabling pilots to adjust their approach without needing to manipulate the throttle excessively. This capability is crucial in various flight scenarios, such as navigating through controlled airspace or adhering to specific altitude constraints. By selectively increasing drag, speed brakes can help pilots maintain the ideal approach speed and configuration for landing while facilitating a more stable descent.