Originally Posted by
puntosaurus
That whizzy Tim Tucker app is for the normally aspirated Raven, not the fuel injected Raven II that you are flying.
I appreciate this. I was showing the chart only as an example for clarification, as some Ppruners here didn't see the point. (I am actually using the Tim Tucker app for the R44 II, and can recommend it all round.)
what's important to note is that at low density altitudes the engine is capable of producing more torque than the drive train is rated for so you can easily pull more than the MAP chart says but in doing so you are over torquing the gearbox.
That is agreed, but not the point of this threat.
MAP chart is giving you a theoretical maximum for full throttle ... Keep pulling collective here past the MAP placarded value and the RPM will droop.
This
is what this threat is about. Actually, about what could be wrong if the RRPM does
not droop despite the placard saying it will droop.
Interestingly enough, two Ppruners suggested that maybe nothing is wrong. That it could be a sign of a 'stronger' engine, in that our R44 Raven II possibly just has a more efficient induction system (e.g., cleaner air filter), allowing the full-throttle MAP to come almost equal to station (ambient) pressure.
But we will also check out a possible leak in the vacuum line to the MAP gauge. Many thanks again to those who have applied their mind to the problem presented.