How many hours should a crew wait before reporting to duty after donating blood?

The correct response is based on the standard medical guidelines regarding blood donation and recovery times for individuals who are in physically demanding roles, such as flight crew. After donating blood, the body requires adequate time to replenish the lost volume and restore blood levels to ensure that an individual can perform their duties safely and effectively.

Typically, it is recommended that individuals wait at least 72 hours before returning to strenuous activity or duties that require high levels of concentration and physical capability, such as operating an aircraft. This time frame allows the body to recover from the donation, minimizing the risk of dehydration, fatigue, and other complications that could impair performance.

The other options do not provide sufficient recovery time based on medical recommendations. Waiting 24 or 36 hours may not allow for adequate recovery, especially for individuals who operate in high-stakes environments where alertness and stamina are critical. A 48-hour wait, while better than the shorter options, still doesn’t align with the safest practices endorsed by health authorities. Thus, a 72-hour wait is the most prudent guideline for crew members to ensure their readiness and safety after donating blood.