What are the oxygen requirements for Part 91?

The correct answer outlines specific regulations regarding oxygen usage for pilots and crew under Part 91 of the Federal Aviation Regulations, which govern general aviation operations. According to these regulations, supplemental oxygen is required to be used when flying at altitudes above 12,500 feet for more than 30 minutes. This requirement is in place to ensure the safety of the crew by preventing hypoxia, a condition caused by insufficient oxygen.

Additionally, the regulation states that above 14,000 feet, oxygen is mandated for the crew during all flight operations. This tiered approach to oxygen requirements is aimed at different altitude bands, addressing the increased risk of oxygen deprivation as altitude increases.

Understanding these requirements is crucial for pilots to maintain safety standards and ensure they are compliant with legal regulations while operating aircraft at higher altitudes where lower atmospheric pressure affects oxygen availability.