What is the function of a stability augmentation system (SAS)?

A stability augmentation system (SAS) is designed specifically to enhance control response and improve the overall stability of an aircraft during flight. This system assists pilots by providing automatic adjustments to control inputs in various flight conditions, especially in turbulence or when the aircraft is subjected to external disturbances. By doing so, it allows for smoother handling and reduces pilot workload, making the aircraft easier to control and more stable.

This capability is especially important in instrument flying conditions, where precision and stability are crucial for safety and performance. The SAS works to maintain the aircraft's desired flight path, so pilots can focus on navigation and system management rather than constant control corrections.

In contrast, increasing fuel efficiency is generally managed by optimizing flight profiles and engine performance, while weather monitoring is unrelated to stability augmentation. Additionally, lowering an aircraft's altitude pertains to altitude management rather than stability. Thus, enhancing control response and stability is the primary and correct function of a stability augmentation system.