Which factor is NOT part of the IM SAFE checklist?

• A. Illness
• B. Medication
• C. Stress
• D. Sleep

Answer: (D)

IM SAFE is a quick preflight self-check pilots use to determine if they’re fit to fly. It lists Illness, Medication, Stress, Alcohol, and Fatigue as factors to assess. Sleep isn’t named as a separate item in this checklist; fatigue is the factor that represents the impact of insufficient rest and ongoing tiredness on your performance. So the factor that isn’t part of IM SAFE is Sleep, because fatigue covers the tiredness you might feel from not sleeping well, rather than listing sleep as its own item. The other factors fit because illness can affect health, medication can cause side effects, stress can impair decision-making, and alcohol impairs judgment and abilities.