Engine startup modelling

[markadeane 272]

I'm really pleased to see that the engine EGT rises smoothly now on startup, thanks guys! However I notice that the N1 spools up to a point in the mid teens then - as the starter toggle clicks back into the off position - very rapidly rises to the idle RPM. Is this how it actually happens? I honestly don't know so I'm curious to see if this is RW behaviour.Also the spool up and down (down more so) seems quite fast, especially for an engine with a fairly big N1 fan, 'rotational inertia/momentum' I think it's called, high school physics was a long time ago for me!Again, this might actually be realistic but I don't know. Can anyone with RW 747 experience comment?ThanksMarkPS: This is not meant to be a 'PMDG got it wrong' post. I simply don't have the experience to state categorically that it is incorrect, hence my appeal for expert comment!

[Datalink 26]

I may be wrong, but as far as I understand, N1 refers to the large fan at the front of the engine, N2 and N3 (on the RR's) refer to the small compressor/turbines in the engine core. Therefore once the engine is turning, I would imagine this has a fairly rapid rise.

[xkoote 57]

Don't know about the speed of power rise and fall but this might be an appropriate post to add this to.I have now noticed that fuel flow doesn't rise until the engine is stabilised. Don't think it's realistic. If this had to be done to increase reality I have no prob with it. It's just that my callouts don't work anymore : (Starter ON -> Rotation -> Oil pressure -> N1 -> (Fuel flow) -> Light up! -> Starter OFF -> Engine Stabilised)Xander

[markadeane 272]

*Bump*Anyone else want to comment on this?:)