Which doors should never be opened if an aircraft is ditched?

When an aircraft is ditched, it is crucial to understand which doors can be safely opened in order to prevent further danger to passengers and crew. The correct choice indicates that passenger and service doors should never be opened in this scenario.

Opening passenger and service doors in a ditched aircraft can create significant hazards, as these doors lead directly to the exterior of the aircraft, which may be submerged in water. If such doors are opened, water could rush into the cabin, potentially leading to flooding that could incapacitate passengers, hinder evacuation, and complicate rescue efforts. The cabin needs to remain intact to provide a safe space until everyone is able to exit the aircraft in a controlled manner.

Although there might be safety measures built into emergency exits and overwing exits to prevent water ingress, they are designed for specific circumstances such as a land evacuation or controlled cabin depressurization. In a ditch scenario specifically, it's critical to maintain as much of the cabin integrity as possible until it is deemed unequivocally safe to exit, making the passenger and service doors the most dangerous to open.

Understanding the operational protocols during an aircraft ditching greatly enhances the safety of those on board, emphasizing the importance of following established safety guidelines during emergencies.