After how long can an ACM fly following a blood donation of 200ml or more?

The correct answer is 72 hours, which is based on the guidelines provided for aviation crew members after donating a significant amount of blood, such as 200ml or more. This time frame is established to ensure the safety and well-being of the individual, as well as the safety of passengers and crew during flight operations.

Following a blood donation, especially one of this magnitude, the body requires time to replenish the lost blood volume and recover from the physiological effects of the donation. The waiting period allows for sufficient recovery of hemoglobin levels and overall blood volume, minimizing the risk of fatigue, dizziness, or other complications that might compromise an individual's performance as a crew member.

By adhering to the 72-hour guideline, aviation authorities ensure that crew members are fit for duty, maintaining both personal safety and the safety of all involved in the flight. The decision to implement a specific recovery period underscores the importance of physical readiness in the high-stakes environment of aviation.