What action should No 2 take after hearing a scraping sound or loud bang?

In the context of an aircraft emergency, hearing a scraping sound or loud bang can indicate a potentially serious situation that requires immediate attention. The most appropriate action for No 2 is to inform No 1 immediately. This choice is crucial for several reasons.

First, No 1, who typically holds a supervisory or command role, needs to be made aware of any unusual sounds or potential hazards to assess the situation effectively. The timely communication of such information can facilitate a quicker and more informed response to the issue, as No 1 might have additional information or training to take appropriate further actions.

Additionally, informing No 1 allows for a coordinated response among crew members. Safety procedures in an aircraft setting emphasize teamwork and clear communication during emergencies. Therefore, by relaying this information, No 2 ensures that the crew can make informed decisions on how to proceed, which might include assessing the need for securing passengers or even evacuating, depending on the circumstances.

The other options, while they may seem relevant, do not prioritize immediate communication with the supervising crew member, which is critical in managing any aircraft emergency effectively.