Which of the following should NOT be done on a power down procedure with passengers on board?

The correct reasoning for not powering down the aircraft while passengers are on board is primarily centered around safety and the welfare of the passengers. Conducting a power down procedure while passengers are still in the cabin can create various risks and challenges, such as potential evacuation needs or loss of essential cabin systems that ensure passenger comfort and safety.

When passengers are on board, the systems in the aircraft, including lighting, air circulation, and emergency systems, must remain operational to ensure the safety of everyone aboard. Thus, maintaining power is crucial until passengers are safely deplaned.

Other actions like conducting a safety briefing, clearing the cabin, and performing maintenance checks can be done effectively while the aircraft remains powered up, as these tasks do not pose the same immediate risk to passenger safety as powering down would. Powering down prematurely could introduce confusion and potential safety hazards for those still aboard.