At a speed below Mach 0.52, which anti-ice should be turned on?

At a speed below Mach 0.52, which anti-ice should be turned on?

• A. Wing and STAB anti ice
• B. Engine A/I only
• C. All three systems
• D. None of the above

Answer: (A)

When icing is a concern at lower speeds, the surfaces most at risk are the wing leading edges and the horizontal stabilizer leading edges. The procedure for this speed range calls for keeping those surfaces protected, while avoiding unnecessary use of engine anti-ice unless the conditions specifically require it. At speeds below Mach 0.52, turning on wing anti-ice and stabilizer anti-ice provides the needed protection for the primary surfaces that ice can rapidly affect during approach or in moist air, without the extra bleed-air load of engine anti-ice. So the best choice is to have wing and stabilizer anti-ice on.

When icing is a concern at lower speeds, the surfaces most at risk are the wing leading edges and the horizontal stabilizer leading edges. The procedure for this speed range calls for keeping those surfaces protected, while avoiding unnecessary use of engine anti-ice unless the conditions specifically require it. At speeds below Mach 0.52, turning on wing anti-ice and stabilizer anti-ice provides the needed protection for the primary surfaces that ice can rapidly affect during approach or in moist air, without the extra bleed-air load of engine anti-ice. So the best choice is to have wing and stabilizer anti-ice on.