To have pressure regulator shutoff valve open and regulate bleed air pressure for engine anti-ice at 16 PSI, engine anti-ice switch must be in which position?

To have pressure regulator shutoff valve open and regulate bleed air pressure for engine anti-ice at 16 PSI, engine anti-ice switch must be in which position?

• A. OFF
• B. AUTO
• C. ON
• D. TEST

Answer: (C)

Engaging the anti-ice bleed path requires turning the engine anti-ice switch to ON. When this switch is ON, the pressure regulator shutoff valve is commanded to open, allowing bleed air to flow and be regulated to the target pressure of about 16 psi for engine anti-ice. In the OFF position, the valve stays closed, so no bleed air reaches the anti-ice system. AUTO relies on system logic and icing conditions to control bleed air flow but does not guarantee the valve is opened to the 16 psi setting unless the switch is ON. TEST is for diagnostic checks and is not used for normal operation. So, to have the valve open and regulate bleed air at 16 psi, the switch must be ON.

Engaging the anti-ice bleed path requires turning the engine anti-ice switch to ON. When this switch is ON, the pressure regulator shutoff valve is commanded to open, allowing bleed air to flow and be regulated to the target pressure of about 16 psi for engine anti-ice. In the OFF position, the valve stays closed, so no bleed air reaches the anti-ice system. AUTO relies on system logic and icing conditions to control bleed air flow but does not guarantee the valve is opened to the 16 psi setting unless the switch is ON. TEST is for diagnostic checks and is not used for normal operation. So, to have the valve open and regulate bleed air at 16 psi, the switch must be ON.