Factor of safety for rotary blades

[lilMissMindset]

anybody here who knows the factor of safety for rotating blades? ASAP. thanks!

 

[SteamKing]

What kind of rotating blades? A helicopter? The propeller on a ship or an airplane? The blades in a blender or a cake mixer?

 

[AlephZero]

Preferably, greater than 1.

But a simple idea like "factor of safety" isn't very useful for "high tech" rotating machines. It's more about doing a risk analysis of the consequences of failure, and designing the machine to mitigate those consequences.

As a simple example, if a helicopter rotor blade tries to pick a fight with a large bird (e.g. a swan) with mass say 8 pounds, the blade will lose every time. The "factor of safety" comes from not picking the fight, not from design of the blade.