What happens to outflow valve control when ram air is introduced at low differential pressure?

The correct answer is that the outflow valve opens partly to allow airflow. This is important because when ram air is introduced into the cabin at low differential pressure, it helps to maintain an appropriate environment within the aircraft.

At low differential pressure situations, the introduction of ram air aids in ventilating the cabin, and the outflow valve's partial opening allows for the correct balance of inflow and outflow air, maintaining cabin pressure while providing necessary airflow. This function is crucial in preventing excessive pressure buildup in the cabin and helping to regulate the temperature and air quality for passengers and crew.

If the valve were to remain completely closed or open fully, it would either inhibit adequate airflow, leading to discomfort and potential pressure imbalances or allow too much air to escape, which could lead to other operational issues like cabin altitude changes. By opening partly, the outflow valve effectively manages the airflow to ensure a comfortable cabin environment while accommodating changes in pressure conditions.