True or False: Oxygen is required for all crew and 10% of passengers above 10,000 feet for flights longer than 30 minutes.

The statement is false because the requirement for supplemental oxygen varies based on the altitude and duration of the flight. According to aviation regulations, all crew members must have access to oxygen when flying above 10,000 feet, but this requirement for passengers only applies when the aircraft is above 14,000 feet for more than 30 minutes. At altitudes between 10,000 and 14,000 feet, oxygen is only required for the crew and not for passengers, and there is no stipulation to provide oxygen for a certain percentage of passengers at these altitudes.

In context, this clarifies why the other options may not align with regulations or operational requirements. Understanding these altitude and duration parameters is crucial for ensuring safety and compliance during flight operations.