If you are
flying between 12,500 feet MSL, up to and including 14,000 feet MSL, the flight
crew needs to use supplemental oxygen if the flight duration in this level
exceeds 30 minutes.
At and
above 14,000 feet MSL up to and including 15,000 feet MSL, the flight crew
needs supplemental oxygen the entire flight time.
At and
above 15,000 feet MSL, all occupants need to be provided supplemental oxygen.