Certified Flight Instructor - Flight Instructor Airplane Practice Exam

At what altitude is supplemental oxygen recommended when flying at night?

1. 5,000 feet.

2. 10,000 feet.

3. 12,500 feet.

4. 15,000 feet.

The correct answer is: 5,000 feet.

Supplemental oxygen is recommended for use at altitudes above 10,000 feet during night flights because at these elevations, the reduced availability of oxygen can adversely affect pilot performance and night vision. The human body generally begins to experience hypoxia at altitudes around 10,000 feet, which can lead to impaired cognitive functions and decreased visual acuity, both of which are critical for safe night flying. At altitudes above 12,500 feet, the FAA and general aviation guidelines suggest that pilots should use supplemental oxygen for flight durations longer than 30 minutes. Above 14,000 feet, the requirement for supplemental oxygen becomes even stricter, as pilots must use oxygen continuously. Therefore, the recommendation for supplemental oxygen around 10,000 feet during nighttime operations is based on the increased susceptibility to hypoxia in less than optimal visibility conditions, which can be particularly dangerous for pilots. This makes effective use of supplemental oxygen crucial for maintaining safety and operational efficacy while flying at these altitudes.