Which AFCS component's inputs are not perceivable by the pilot through the flight controls?

• A. Beep Trim
• B. SAS
• C. Autopilot
• D. SAS/AP Cut

Answer: (B)

Automatic stabilization systems work in the background by using sensors and internal control loops to nudge the surfaces, rather than requiring a direct, conscious input from your hands. The stabilization augmentation system processes those sensor signals and applies small corrections through actuators, but you don’t feel a distinct “SAS input” when you touch the controls—the corrections are internal and mainly influence how the aircraft behaves rather than how you must move the controls. In contrast, the autopilot commands surface movement that you can sense through the control yoke, and trim changes also affect the forces you feel at the controls. So the component whose inputs aren’t perceivable through the flight controls is the stabilization augmentation system.