Actually - the red line is at 25" and is NEVER allowed under ANY alt/temp combinations according to the POH. If you get anywhere near the red line you can guarantee you've busted a limit no matter what the ambient conditions.
The maximum according to the checklist in front of me here is 23.2" continuous and 24.1" maximum at sea level if it is 40C outside. So why isn't the red line at 24"?
I don't have a POH with me but I'm pretty sure that you can find a combination of alt/temp which reaches the redline, maybe you are mixing up the R22 models, I can't remember as its been a while.
I recall taking off one day from my garden with 2 fat boys on board when I was faced with a choice - it was either trim the rotor blades on a telegraph pole or exceed the limitation. I chose to exceed the limitation.
A chat with the engineer later on reassured me that all was well.
Both the 22 and 44 have more power available than the red line indicates.
It is there on the rare occasion that you need the extra power to prevent rolling the machine up into a ball.
Your last sentance is correct but is NOT to be used in the example you gave as you were fully aware before takeoff that you were overweight and were therefore willingly over torquing the transmission. Again, the MAP guage is not there for engine limitations but is to show you how much engine power you can use for the current ambient conditions in order not to exceed the TRANSMISSION limitations. Exactly the same rules apply to your new R44. The red line on the MAP guage is not to be used as a limit except when certain conditions exist, I wish they'd just get rid of the damn thing (the red line, not the R22
) and save a lot of confusion.
Cheers
TS