Which procedure increases holding time when deicing/anti-icing an airplane using a two-step process?

The correct choice involves using heated Type 1 fluid followed by cold Type 2 fluid, which is an effective strategy when it comes to managing holding times during deicing and anti-icing processes. Heated Type 1 fluid is designed to remove any existing ice or snow and serves as an effective deicing agent. By applying this warm fluid first, it helps to ensure that the critical areas of the aircraft are cleared of contaminants.

Following that with cold Type 2 fluid has a particular benefit. Type 2 fluid is formulated with thicker properties that help prevent the adherence of ice and snow, maintaining the aircraft's clean surfaces for a longer period of time after the deicing process. The transition from hot to cold creates a beneficial effect, as the cold Type 2 fluid helps to maintain the deiced surfaces, increasing the holding time before the aircraft needs to be treated again.

In contrast, other options may not maximize the efficiency and effectiveness of the deicing/anti-icing process. For instance, using fluids that do not adequately transition from deicing to anti-icing may leave the aircraft more vulnerable to re-icing. Thus, the combination of heated Type 1 fluid followed by cold Type 2 is optimal for effectively managing holding times against ice and