Which sequence of events correctly describes holdover-related deice/anti-ice procedures?

• A. Final application, holdover time, takeoff
• B. Final application, pre-takeoff check, holdover time
• C. Final application, holdover time, pre-takeoff check
• D. Holdover time, final application, pre-takeoff check

Answer: (C)

The main idea is the order in which deice/anti-ice actions and checks are done after icy conditions are present. After the final application of the deicing/anti-icing fluid, a holdover time starts, which is the window during which the protection from that fluid is expected to last. You then perform the pre-takeoff check while still within that holdover window to verify the aircraft is ready and the protection remains effective. Only after that do you proceed to take off if you’re still within the holdover time.

That’s why the sequence is final application, holdover time, then pre-takeoff check. If you tried to start holdover before finishing the final application, or you did the pre-takeoff check before or outside the holdover period, it wouldn’t align with how holdover protection is defined and verified. The other options place holdover time at the wrong point or omit the needed pre-takeoff check within the protective window.