Anytime you have a spinning prop on a plane it's always dangerous, not sure it matters if it's a 11x5 or the 13x8 ( 3 blade ) that i'll be running, they both can do damage, but if you know what you are doing and take all the safety precautions then accidents are less likely. This engine will be mounted on a rubber isolated mount and the firewall has been reinforced so only if the whole plane breaks apart will the engine fall off.

For the beginners: DON'T TRY THIS AT HOME