What is the purpose of the flight deck door’s access control?

• A. To shorten boarding time.
• B. To enable unrestricted entry by all crew.
• C. To maintain in-flight entertainment.
• D. To prevent unauthorized entry, restrict access to authorized crew, and maintain security while allowing controlled entry.

Answer: (D)

Access control for the flight deck door is about securing the cockpit from unauthorized people while still allowing entry for those who are authorized. The door is kept locked and requires verification or a controlled process to open, so only pilots and other approved crew can gain access. This protects against intruders or inappropriate access during flight, helps manage security threats, and lets the crew grant entry when appropriate through established procedures (like intercom and a verified request). It is not intended to speed up boarding, grant unrestricted access to everyone, or support entertainment systems.