For decompression of less than 4 hours, how long should one wait before flying?

For decompression events lasting less than 4 hours, waiting for 12 hours before flying is considered a suitable duration. This waiting period is based on the body's requirement to off-gas nitrogen absorbed into tissues under pressure, which can pose a risk for decompression sickness (DCS) when ascending to lower pressures, such as at flight altitudes.

The rationale behind the 12-hour guideline is to allow sufficient time for the body to eliminate excess nitrogen. After a decompression incident, the longer the wait, the higher the safety margin against potential DCS, given that the potential for bubble formation in the tissues decreases over that timeframe.

Choosing a duration shorter than 12 hours would not provide enough time for adequate off-gassing and increases risk, while durations longer than 12 hours would be more conservative and unnecessary for decompression events of this brief nature. Thus, 12 hours strikes a practical balance between safety and operational readiness for flight.