Wing anti-ice valves require an electrical signal and pneumatic pressure to open.

Wing anti-ice valves require an electrical signal and pneumatic pressure to open.

• A. True
• B. False
• C. Only electrical
• D. Only pneumatic

Answer: (A)

Wing anti-ice uses bleed air to heat the wing leading edge, and the valve that meters that bleed air is electro-pneumatic. An electrical signal from the controls commands the valve, but the actual movement is provided by a pneumatic actuator powered by bleed-air pressure. So both the electrical command and the available pneumatic pressure are required for the valve to open. If either condition is missing, the valve cannot open, preventing unintended bleed-air flow.

Wing anti-ice uses bleed air to heat the wing leading edge, and the valve that meters that bleed air is electro-pneumatic. An electrical signal from the controls commands the valve, but the actual movement is provided by a pneumatic actuator powered by bleed-air pressure. So both the electrical command and the available pneumatic pressure are required for the valve to open. If either condition is missing, the valve cannot open, preventing unintended bleed-air flow.