What phenomenon does induction icing refer to?

Induction icing refers to the process where water vapor in the air cools and freezes into ice due to a decrease in pressure as it moves through the engine's intake system. When air passes through an area of reduced pressure, such as a duct in the engine, it expands, resulting in a drop in temperature. This cooling can cause any moisture in the air to condense and freeze, leading to the formation of ice.

This phenomenon is particularly critical in aircraft operations, especially during climbing and descending phases when engine intake pressure changes can be significant. Understanding induction icing is important for pilots and engineers to prevent engine malfunction or performance issues due to ice buildup.

Other options, while related to the broader concept of icing in aviation, do not accurately describe the specific nature of induction icing. For instance, the build-up of ice in the fuel system pertains to fuel-related icing rather than the pressure-induced icing occurring in the intake air ducts. The occurrence of icing at low altitudes during landing represents a different scenario, focusing on environmental conditions rather than induction mechanics. Lastly, ice forming along the airframe at high speeds speaks to aerodynamic icing, which involves different conditions and factors impacting aircraft surfaces rather than the engine induction process itself.