Flight crewmembers may not donate blood within ____ hours prior to going on duty, except in emergencies.

Flight crewmembers may not donate blood within ____ hours prior to going on duty, except in emergencies.

• A. 12
• B. 24
• C. 48
• D. 72

Answer: (B)

Donating blood can temporarily lower blood volume and the body’s oxygen-carrying capacity, which can affect a crewmember’s alertness, endurance, and overall performance during demanding flight duties. Waiting at least 24 hours before going on duty gives the body time to recover and helps prevent symptoms like dizziness, fatigue, or fainting that could compromise safety in the high-stress, high-ops environment of flight. The exception for emergencies recognizes that life-saving needs can override this precaution. The 24-hour window strikes a balance between safety and practicality, whereas shorter windows don’t provide enough protection and longer windows would be unnecessarily restrictive.

Donating blood can temporarily lower blood volume and the body’s oxygen-carrying capacity, which can affect a crewmember’s alertness, endurance, and overall performance during demanding flight duties. Waiting at least 24 hours before going on duty gives the body time to recover and helps prevent symptoms like dizziness, fatigue, or fainting that could compromise safety in the high-stress, high-ops environment of flight. The exception for emergencies recognizes that life-saving needs can override this precaution. The 24-hour window strikes a balance between safety and practicality, whereas shorter windows don’t provide enough protection and longer windows would be unnecessarily restrictive.