What should you always assume about a propeller?

• A. They are always hot
• B. They are always cool
• C. They spin slowly when off
• D. They pose no hazard when stationary

Answer: (A)

The safety concept here is that propellers can cause burns and injuries, so you must treat them as potentially hot and hazardous even when they’re not moving. After use, blades can retain heat from friction and exhaust, so touching a blade or stepping into the arc can burn you. That’s why the best choice is to always assume a propeller could be hot and to let it cool before handling or approaching it. Thinking they’re always cool would ignore the burn risk; assuming they spin slowly when off isn’t reliable since they won’t necessarily do so and you shouldn’t rely on motion cues to stay safe. And assuming there’s no hazard when stationary ignores the danger of contact or unexpected movement if the engine is started or a gust of wind moves the blades.