Aeromedical factorsQuestion 736 of 934

How does carbon monoxide (CO) affect the blood, according to the handbook?

  1. CO attaches to hemoglobin about 20 times more easily
  2. CO leaves the body within about 1 hour after exposure
  3. CO has a strong smell that warns the pilot of danger
  4. CO attaches to hemoglobin about 200 times more easily
Show answer

Correct answer: CO attaches to hemoglobin about 200 times more easily

CO prevents hemoglobin from carrying oxygen. The body needs up to 48 hours to dispose of CO.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 17: Aeromedical Factors — Carbon Monoxide (CO) Poisoning, page 434

Practice aeromedical factors

Questions last reviewed: 18 October 2026