Hello Aerobat77,
Thanks for answering,
No, I think the guy you mean is Marcel, another guy who is also interested in PT6A operating principle, but for another simulator ( but same purpose )...
No, as I told earlier in this thread, I can speak with a real PC-6 pilot about every weeks, but the deep Bęta use and principle is dark to many pilots, only engineers and some mechanic can clearly tell you what actually happens behind the scenes...
In the simulator, I can achieve the dive performances ( 110-115 Knots, - 6500 Ft/min, -40° pitch angle ) with a " flat " pitch of -0°30', and Np don't go beyond 2200 RPM until the plane don't go over 140 Knots ( then the governor increase pitch to reach again the governing range ). All I said is of course, assuming Prop lever is full forward.
But in this case, in short final, if you suddenly retard Power lever against idle stop, you will create so much drag that you'll stall ( in short final, 38° flaps, you want to be at 61 Kts.. ) So what is preventing ? In an old PC-6 PoH, I read that flight idle prop pitch was +9°30', and so, even when blades are resting against low pitch stops, it never create negative or zero thrust, so no worries if you retard power to idle in final, while the airspeed is low.
The question now is, what allow the prop to be at flat pitch in flight, and what DON'T allow it not to be flat in final, or other critic flight situations. Cause I'm sure there is some kind of protection to not enter in flat pitch in final approach..
BUT, there are procedures written in the manual about " Bęta approach ".. so, there is obviously a relation between that..
And here is my total lack of info
Last edited by Hueyman; 17th Nov 2012 at 14:25.