Certified Flight Instructor - Flight Instructor Airplane Practice Exam

If an individual has gone scuba diving which has not required a controlled ascent and will be flying to cabin pressure altitudes of 8,000 feet or less, the recommended waiting time is at least?

1. 4 hours.

2. 12 hours.

3. 24 hours.

4. 1 hour.

The correct answer is: 12 hours.

When considering the physiological effects of scuba diving on flying, it's important to focus on the principles of decompression sickness and how nitrogen is absorbed and released in the body. After scuba diving, especially at depths that involve greater pressures, nitrogen is absorbed into the body tissues. If a diver ascends too quickly or flies too soon after a dive, the reduced cabin pressure can cause the nitrogen to come out of solution rapidly, potentially leading to decompression sickness. For dives that do not require a controlled ascent, the recommended waiting time to allow adequate nitrogen elimination is typically 12 hours if you plan to fly to cabins at altitudes of 8,000 feet or less. This guideline is set to provide a safe margin of time for the body to off-gas the nitrogen that has been absorbed during the dive, thus reducing the risk of developing decompression illness. This precaution is especially important for pilots and passengers as the effects of altitude may compound the risk involved with residual nitrogen in the body. Waiting the advised 12 hours ensures that the risk is minimized and aligns with standard safety practices established by aviation and diving authorities.