Which sensors deactivate the stall warning horn?

The stall warning horn is an important safety feature in multi-engine aircraft, designed to alert pilots when the aircraft is nearing a stall condition. This system typically relies on a series of sensors that monitor the aircraft's configuration, particularly the position of the flaps.

When the flaps are extended to specific settings, the aerodynamic characteristics of the aircraft change, which can alter the stall characteristics. In this case, when the inboard flaps are set to either 25 or 40 degrees, the stall warning horn is deactivated. This is designed to prevent the horn from activating during configurations where the aircraft is expected to operate safely, such as during approach and landing, where the aircraft will typically be at reduced speeds and higher angles of attack.

Understanding why the stall warning horn is deactivated at these flap settings is crucial for pilots. It prevents unnecessary alerts during phases of flight where the aircraft's operating parameters are normal and expected, allowing pilots to focus on their approach and landing without being distracted by false stall warnings.

The other configurations indicated by the other choices involve either outboard or inboard flaps set at different degrees that do not meet the criteria required to deactivate the stall warning horn, thus maintaining an alert for the pilot to enhance safety during critical phases