Before leaving an aircraft unattended, what must be ensured?

To address the question about what must be ensured before leaving an aircraft unattended, the correct choice emphasizes the importance of safety and security in aviation operations. Ensuring that all doors leading to and from the loading bridge are closed is crucial because it protects against unauthorized access to the aircraft and prevents any potential security breaches.

When doors are left open, it could lead to risks such as theft, tampering with aircraft systems, or even potential safety hazards if someone inadvertently enters the aircraft. Closing all doors helps secure the aircraft until the next phase of operations, whether that be boarding passengers or preparing for a departure.

Other choices, while they may be important considerations in the context of aircraft operations, do not directly relate to the immediate requirement of ensuring the aircraft’s security while unattended. For instance, ensuring all passenger seats are clear pertains more to cabin service procedures than security. The fuel status is critical, but it relates to operational readiness rather than the security of the aircraft when it is unattended. Similarly, while having the cargo hold locked is important for securing cargo, it does not specifically pertain to the immediate actions required when leaving the aircraft unattended compared to securing entry points.

Therefore, the focus on closing all doors reflects the vital priority of safeguarding the aircraft and its