Which of the following is NOT an input to the Q feel system?

The Q feel system in aircraft is designed to provide feedback to pilots regarding the aerodynamic forces acting on the aircraft, enhancing their control and handling of the aircraft. Its inputs typically include elements that directly influence how the aircraft behaves in flight.

Static and dynamic pressure are vital to understanding the airflow around the aircraft, as they help determine lift and drag. The control surface angle of deflection allows the system to gauge how pilot inputs are resulting in changes in aircraft attitude and performance. Air temperature can impact air density and hence influence the aerodynamic calculations necessary for the system to function effectively.

While altitude of the aircraft does have implications for flight dynamics, it is not a direct input to the Q feel system in terms of providing moment-to-moment feedback. Instead, it's more relevant in a broader context of flight operations and performance, which does not serve as an immediate input to the Q feel system's feedback mechanism. Thus, altitude does not provide the localized aerodynamic information necessary for the Q feel's operation, distinguishing it from the other inputs that focus on immediate aerodynamic conditions.