load spectrum and usage spectrum 2

To predict the fatigue life of "dynamic" or "life-limited components", we need to measure the loads produced during diffferent manoeuvres. This gives us an idea of which manoeuvres are more fatigue damaging. How often does an operator fly this manoeuvre in 1000 flight hours?

This is where the usage spectrum comes in. Some operators fly this type of fatigue-damaging manoeuvre more than others. The usage spectrum gives you an idea of how often each manoeuvre is performed. Heli-loggers, for example can expect significant fatigue penalties on their dynamic components...

Here's an old report that might help...

Thanks