What is one of the requirements for aircraft operating above 14,000 feet?

Operating an aircraft above 14,000 feet presents unique physiological challenges, primarily due to the reduced availability of oxygen at higher altitudes. One key requirement is that passengers must use supplemental oxygen when flying at these altitudes. Specifically, when flying above 14,000 feet MSL (Mean Sea Level) for more than 30 minutes and for any flight above 15,000 feet, the regulation mandates that passengers must utilize supplemental oxygen to avoid hypoxia, which can impair judgment, coordination, and overall cognitive function.

While crew members are also required to use supplemental oxygen above certain altitudes—specifically, above 12,500 feet MSL for flight durations over 30 minutes—this requirement emphasizes the need for passenger safety as well. Maintaining adequate levels of oxygen is crucial for ensuring that everyone on board remains alert and functional, and it's an essential safety measure when operating at these higher elevations.