What happens to the HYD 3B pump when the ADG deploys?

When the ADG (Air Driven Generator) deploys, the HYD 3B pump is designed to automatically turn on to ensure hydraulic pressure is available to critical systems. This automatic activation occurs regardless of the switch position, providing essential hydraulic power to maintain aircraft functionality during an emergency situation.

This mechanism is vital because, during deployment of the ADG, the aircraft may be transitioning to emergency power and needs reliable hydraulic support to maintain control and operation of systems. Thus, the HYD 3B pump's activation contributes to the overall safety and redundancy of hydraulic power in a situation where other power sources may have failed.

The other options do not account for the automatic nature of this pump activation in relation to the ADG deployment, which is why they are less appropriate in describing the system's response during such a scenario.