What is a key feature of the torch once it is activated?

The key feature of the torch once it is activated is that it illuminates automatically. This means that as soon as the torch is turned on, it provides a steady light source without requiring any additional steps or adjustments from the user. This automatic function is essential for ease of use, especially in emergency situations where quick accessibility and readiness are vital.

In the context of aviation safety, the ability for the torch to illuminate immediately ensures that crew members can swiftly address issues or provide assistance when needed. The design emphasizes reliability and immediate usability, which is crucial for maintaining safety and efficiency during operations.

While the other options may reflect features that are relevant in different contexts, they do not apply to the core functionality of the torch itself once activated. For instance, requiring further adjustments or cycling through brightness levels would complicate its use, and connection to an aircraft's power system might not be applicable if the torch is designed to operate independently. Therefore, the automatic illumination feature is distinct and fundamental to the torch's intended use.