What are the two main functions of the speed brake?

The speed brake serves two primary functions: to decelerate the aircraft and to increase the descent rate without leading to an increase in airspeed. When deployed, the speed brakes create additional aerodynamic drag, which helps to slow the aircraft down effectively. This is especially useful during descents, as it allows the pilot to control the descent rate precisely without needing to adjust engine power or alter the pitch significantly.

Using the speed brake can help maintain a safe airspeed while allowing you to descend more rapidly. This capability is crucial during landing approaches where timing and altitude management are essential. The design aims to enhance the aircraft's control during slower flight regimes, making it easier for pilots to manage the transition from cruising to landing conditions.