Originally Posted by
aa777888
Sadly, there is no information in the POH that will allow that to be done.That's a required, pre-takeoff checklist item. to calculate 5 minute max. and max. continuous vs. OAT. A lot of folks tend to forget about it after takeoff, though, and never look at the OAT again.
Again, you can't do that, but you can at least check to see how many inches of MP you've got under 5 minute max. and MCP, which is always a good thing to know.
If you know what your max MP is, which is a preflight item, and you do proper planning to calculate what max could be, based on the warmest forecast temp and highest point of departure then it really isn't rocket science.
Pulling into a hover gives a pretty clear idea of margin to max.
Having a giant display that says 99% isn't going to change much when too many haven't bothered to plan and ignored the subsequent low-rpm alarm.