Under what condition can the PIC exclude someone from the flight deck?

The condition under which the Pilot in Command (PIC) can exclude someone from the flight deck is during an emergency. During emergencies, the focus and decision-making priorities shift significantly to ensure the safety of the aircraft, passengers, and crew. In such situations, the PIC may need to make quick decisions and maintain a clear and streamlined cockpit environment. Excluding individuals from the flight deck may be necessary to reduce distractions and ensure that the crew can effectively manage the emergency.

The ability of the PIC to maintain control over who is present in the cockpit is crucial for ensuring operational integrity and safety. The nature of emergencies often requires full attention and coordination among the crew, and any additional personnel can compromise this focus. Thus, the authority of the PIC to exclude individuals under these circumstances is firmly established in aviation regulations and standard operating procedures.