What is an immediate action during an oxygen low inflow CAS alert above 10,000 ft?

When an oxygen low inflow CAS alert occurs above 10,000 feet, the immediate and most appropriate action is to don oxygen masks. This action is crucial because maintaining an adequate supply of oxygen is vital for the crew and passengers at high altitudes where the air pressure and oxygen levels are insufficient for safe breathing. Using oxygen masks ensures that everyone in the aircraft can receive the necessary oxygen to function properly and remain conscious, particularly in the event of cabin pressure loss or other emergencies.

While clearing the cabin, reducing speed, or preparing for an emergency landing could be relevant responses in different scenarios, they are not the immediate priority when an oxygen alert is triggered. The first step is to address the potential threat to oxygen availability and ensure that all occupants are secured with oxygen masks before considering subsequent actions. This immediate response directly addresses the risks associated with hypoxia at elevated altitudes.