What components are included in an air-cycle cooling system?

An air-cycle cooling system operates primarily by utilizing ambient air to cool components within an aircraft. The correct components that comprise this system include a cooling turbine, air-to-air heat exchangers, and valves.

The cooling turbine is essential, as it expands high-pressure air to a lower pressure, resulting in a significant drop in temperature, which is critical for cooling functions. The air-to-air heat exchanger efficiently transfers heat from the system to the ambient air, utilizing outside airflow to cool the circulating air. Valves play a crucial role in controlling the flow and direction of air through the system to optimize cooling performance and efficiency.

While other options include components that may play roles in different cooling or environmental control systems, they do not accurately describe the specific components or their functions in an air-cycle cooling system. For instance, the presence of a radiator is typically associated with liquid cooling systems, while certain components like turbine blades and an evaporator may be related to entirely different setups, such as refrigeration systems or gas turbine operations. Keeping the context of air-cycle cooling systems in mind helps affirm why the specified components in the correct choice are integral to their operational effectiveness.