At what PSI is a Main O2 inoperable?

The correct answer highlights that the Main Oxygen system becomes inoperable at 800 PSI. In aviation and emergency medical services, maintaining oxygen levels is critical for patient care, particularly during transport in a medical helicopter or ambulance. The specified threshold of 800 PSI ensures that there is adequate oxygen supply for critical situations. If the pressure drops below this level, it may not meet the operational requirements needed for effective patient support and may lead to situations where supplemental oxygen cannot be provided when it is necessary, thus posing a risk to patient safety.

It's essential for crews to monitor oxygen levels closely and know this threshold so that they can replace oxygen tanks before they become inoperable, ensuring ongoing readiness for medical emergencies. Keeping operations within safe pressure limits is a fundamental aspect of patient care protocols in emergency settings.