What happens after communication is established with a pilot returning to the FD?

After communication is established with a pilot returning to the flight deck (FD), a crucial step in ensuring the safety and security of the aircraft involves verifying the pilot's identity. This process is essential for confirming that the individual requesting access is indeed the authorized pilot and not an imposter. Verification typically includes confirming the pilot's credentials, such as their identification or using specific security protocols to validate their identity.

This measure helps prevent unauthorized access to the flight deck, thereby maintaining a secure environment during flight operations. It's an important part of enhancing the overall security protocol in aviation, especially as threats can evolve and the importance of safeguarding the cockpit is paramount.

In contrast, although other options might relate to different operational practices or security protocols, they do not align with the immediate and critical action that follows the establishment of communication with the pilot. For example, the automatic opening of the door (mentioned in another choice) is not a typical response before verifying the pilot's identity, and locking the FD again would occur after the pilot is verified and safely on board. Thus, verifying identity comes first and is a fundamental procedure in maintaining cockpit security.