Crab, you said...
Then you compared an increase in OAT (worsening conditions for the engine with the throttle wide open) between what common sense told you (7300' DA) and what the graph told you (8000'DA).
I assume that you meant to say...
"Then you compared an increase in OAT (worsening conditions for the engine with the throttle wide open) between what common sense told you (7300'
PA) and what the graph told you (8000'
PA)."
As far as my 'common sense' is concerned it wasn't common enough to take into account the improved engine performance at lower pressure altitudes which somewhat compensates for the change in temperatures ( by 58% if my reading of the graph is correct). As for calculating it manually, I'll leave that to a braver man (you!
) It'll be interesting to see what results you get.
As an aside, is it not logical that if performance drops off radically with increased height above the critical altitude (obvious from the graph), that the converse is also true, that performance increases drastically for decreased altitude above the critical altitude?
Irlandés