If you want to be at Idle and you're not sure the NGX is there press F1. I found that leaving my throttle at max after takeoff and A/T arm cured it for me until you revert to manual.

I think this is just how the sim had to mimic real life within the limitation of FSX. In the real jet, the levers are all the way back at idle and can give you varying N1/N2%, based on conditions.

 

The FSX can't do that, so NGX actually moves the TLs to an appropriate "idle" position.

 

That's my take, anyway.

If you have a custom engine model, as I thought the NGX had, then you shouldn't be affected by FSX limitations.  I wonder whether PMDG may have implemented flight idle incorrectly compared to how it is in the aircraft.

If you have a custom engine model, as I thought the NGX had, then you shouldn't be affected by FSX limitations.  I wonder whether PMDG may have implemented flight idle incorrectly compared to how it is in the aircraft.

Dunno. Tabs has repeatedly said they got the engine data direct from Boeing, I believe. So many threads on ending up fast/high makes me think there is a problem somewhere, though. It's a slippery ship, but I see Thrust Required just about as often Drag Required, RW.

Hello again! Thank you all for replies. It's nice to read that there is everything ok with my simulator, but... yesterday, I checked my N1 values one more time, and it was 47%! (after retard and established at "idle"). When the IAS reached programmed 300 knots, N1 didn't decrease and aircraft accelerated rapidly to 310 knots. Only after a while, I could decrease N1 by pressing F1. I ask you again - are you 100% certain that it is normal? I thought that N1 should decrease at the moment of speed changing from Mach to IAS, but you are the experts

47 % is too high. Something isn't right.

Dunno. Tabs has repeatedly said they got the engine data direct from Boeing, I believe. So many threads on ending up fast/high makes me think there is a problem somewhere, though. It's a slippery ship, but I see Thrust Required just about as often Drag Required, RW.

I didn't mean that I thought idle N1 or thrust is wrong, but how approach idle is modelled in the engine fuel control simulation.  There shouldn't be any need to drive the throttle to achieve it.  Idle throttle produces an N2 below the minimum idle governor setting.  So the governor prevents N2 reducing below that setting.  Approach idle merely raises that governor setting.  It may be they correctly implemented it in the engine model but the effect is a spurious throttle movement at high altitude which can result in the engine not achieving the correct idle N1 at lower altitude unless you reset idle with the F1 key.  The first few degrees of throttle movement don't produce any increase in engine RPM.  So it's possible the simulated autothrottle might be increasing throttle angle until it can control N1 That would explain the behaviour where it can be forced to the idle stop then moves back up a few degrees.  If PMDG changed the way the throttle was driven in the ARM state it might correct the issue.

 

Hello again! Thank you all for replies. It's nice to read that there is everything ok with my simulator, but... yesterday, I checked my N1 values one more time, and it was 47%! (after retard and established at "idle"). When the IAS reached programmed 300 knots, N1 didn't decrease and aircraft accelerated rapidly to 310 knots. Only after a while, I could decrease N1 by pressing F1. I ask you again - are you 100% certain that it is normal? I thought that N1 should decrease at the moment of speed changing from Mach to IAS, but you are the experts

That isn't normal.  It isn't what I see in my NGX. Two possibilities come to mind:

 

1. Are you using FSInn weather?  This plays havoc with engine performance at higher altitudes.

2. Did you have any anti-ice selected?  This will increase idle N1 even more than normal.

Ad 1. No, I don't. I use AS2012. TAT is ok (I know FSInn bug)

Ad 2. No, all anti-ice are off.

 

The problem has appeared some time ago. Earlier everything was ok and I've been thinking what did I do since then, what could cause it. Unfortunelly with no result. Maybe FSUIPC? But I've added there some nonlinearity in rudder axis, and nothing else...