What should the PM do if there is no response from the PF after the second challenge?

When faced with a situation where there is no response from the Pilot Flying (PF) after the second challenge, the correct course of action is to verbally announce assuming control of the aircraft. This action is essential because it directly addresses the potential loss of situational awareness or incapacitation of the PF. By verbally announcing the assumption of control, the Pilot Monitoring (PM) clearly communicates the change in authority and responsibility, which is crucial for safety.

This step not only ensures that there is no ambiguity regarding who is in command of the aircraft but also allows for immediate corrective action to be taken if the PF is unable to perform their duties. Effective communication in the cockpit is vital during critical situations, and this announcement plays a key role in maintaining the safety of the flight.

In the context of the other options, conducting a safety briefing might not be timely or appropriate in a scenario demanding immediate action. Initiating emergency procedures without declaring control may lead to confusion regarding who is executing those procedures. Contacting Air Traffic Control (ATC) for assistance is also important but should ideally occur after a clear verbal command has been established to prevent further complications. Verbalizing the assumption of control is therefore the most immediate and direct response to ensure the safety and management of the aircraft