What action does the emergency hydraulic control allow during power loss?

The emergency hydraulic control is designed to provide limited functionality during a power loss situation in the aircraft. In this context, the key components that can be extended using the emergency hydraulic system are critical for ensuring control and safety during an emergency landing or maneuver. The one-time extension of these components typically refers to systems such as landing gear or flaps that require hydraulic power for operation.

This feature is crucial because, in the event of a hydraulic failure, having the ability to extend certain vital systems allows the pilot to safely manage the aircraft’s descent and landing, ensuring that essential features are available even when the primary hydraulic system is compromised.

While landing gear deployment, manual control reversion, and auxiliary flaps may involve aspects of hydraulic systems, the emphasis in the question is on the specific capabilities afforded by the emergency control, which primarily allows for the one-time extension of key components essential for emergency situations.