What indicates oxygen is flowing during a decompression?

The green flow indicator is used to signify that oxygen is actively flowing during a decompression. This color coding is a standard practice in aviation safety and life support systems, as it allows crew members to quickly and easily assess whether oxygen is being delivered to the necessary areas. When the indicator shows green, it gives a clear visual confirmation that the oxygen supply system is functioning correctly, ensuring that the passengers and crew can breathe adequately in low-pressure conditions.

Using color-coded systems, such as green for 'on' or 'active' and contrasting colors for 'off' or 'inactive', enhances communication and safety during critical situations like decompression events. In contrast, other indicators or failure to have no indication may lead to confusion or misjudgment regarding oxygen availability, which is crucial during emergencies.