For flights at or above 14,000 feet, what is the requirement for oxygen in the CRJ 900?

In the CRJ 900, when operating at altitudes of 14,000 feet or higher, the requirement is that oxygen must be available for 100% of the crew. This regulation aligns with safety measures intended to ensure that all crew members have access to supplemental oxygen in the event of a cabin altitude emergency, where the pressure might drop below safe levels.

At these higher altitudes, the atmosphere has significantly less oxygen, which can lead to hypoxia, a condition where the body is deprived of adequate oxygen. Providing each crew member with access to oxygen helps maintain their situational awareness, decision-making capabilities, and overall health, thereby ensuring the safety of both the crew and passengers during flight.

The other options do not meet the regulatory requirements set forth by aviation authorities for high-altitude operations, and therefore ensuring that oxygen is available for the entire crew is critical to flight safety.