Difficult to slow down

[davierosoft 13]

Yes, the 38-40% is pretty sure the idle bug setting25-22% is for ground idleAND IDLE HAS NOTHING TO DO WITH AUTOPILOT it is related to the engine electronic control. So it is the engine that choose its idle.Pilot cannot put throttles more back than IDLE, VNAV descent is done by the AT that moves the throttles to IDLE (except if it requires more thrust for mantaining speed) LVL CHG is te same, and same for other... IDLE is IDLE.However in FSX the F1 and F2 keyboard keys can force the engine to operate to lower values if kept pushed.

[Superpilotv2 2]

Hmm, I hope one of the PMDG boys will chip in and tell whether that is a real problem/bug or just missmanagement on my side.

[rocketfs 2]

Idle should be idle whether you're in VNAV, LVL CHG, or manual flight.22% sounds pretty low for in flight. I imagine you're defeating PMDG's coding for the PMC's variable idle speeds.

Agree. 22% seems to me as Low Idle thus on the ground.Bert Van Bulck

[andysim 0]

ive also seen as high as 42% at altitude and struggle to come down in time, however ive not flown properly since that last update, will try it out tonight. The Throttles would move to fully idle and then creep forwards on thier own.

[davierosoft 13]

Hmm, I hope one of the PMDG boys will chip in and tell whether that is a real problem/bug or just missmanagement on my side.

If your idle is above 37-38% during descent, or it is the idle bug, or you filled incorrectly winds (too much tail wind) in forecast or you are descending with landing gear down or flaps >15... So... it is simple to find if you have the bug.

[Thunderbird8 1]

So... it is simple to find if you have the bug.

And if you have it, what do you do? Please can someone tell us! :(

[kjjj11223344 48]

If your idle is above 37-38% during descent, or it is the idle bug, or you filled incorrectly winds (too much tail wind) in forecast or you are descending with landing gear down or flaps >15... So... it is simple to find if you have the bug.

Agreed. My idle starts at around 40% at about 38000 ft, and gets into the high thirties from there. I sometimes fly with a CI of 100 because I want to get to the destination fast (and I don't pay the gas), and I can descend on vnav until glide slope and localizer capture just fine.

[Superpilotv2 2]

If your idle is above 37-38% during descent, or it is the idle bug

And that´s what i´m having! :( Will this be investigated further by PMDG and adressed in SP2?Well guys, I´ll just make a short test flight from KEUG back to KCLM to check whether it occurs cause of improper FMC settings. I try to set up everything as good as I can.Fuel: 15.000lbGW: ~135.000lbCI: 36CRZ FL: 260And a proper weather prediction as far as I can do it. I´ll report back.

[davierosoft 13]

The better way to make a good test is to use clean sky configuration with no winds 2992 at sea level 15°C.The issue sometimes start at about 15000Ft during descent, so, maybe it can be normal above that altitude.Check also anti ice operation as it influence the idle.Read this topic about the tests made to troubleshoot the problem:In the tables there are a lot of values you can compare.

[Paul Deemer 13]

Paul that list is stunning! Where did you get it??

Off the AVSIM Forums where else? :(

Descending at 330 kts is not too fast. Long before you decelerate to approach speed you would decel to 240 below 10,000ft. So the speed above 10,000 ft has no bearing on the decel from 240 to approach speed.As for the easyJet pilot's advice, I've never been on any flight that descended with speedbrake extended the whole way. That certainly isn't usual. If you find yourself fast you can use speedbrake as much as you need to, maybe that is what they meant.Forget cost index, etc, the best advice is to think ahead. Stay ahead of the aircraft. VNAV should put you in a position where you can slow down to approach without drama. However as captain you need to progressively extend flap and reduce speed, beginning to do so in good time.

Look if it wasn't too fast then people wouldn't be complaining about being able to slow down when they need to. On top of that if the airlines were descending at 330 knots as SOP's then they wouldnt be using low cost index's in the 20-40 range. To descend at 330 knots with VNAV you need a cost index in the range of 100. If most airlines are using 40s or less then why would you not want to follow what the real world airlines are doing?If you wanna use a cost index of 100 and descend at 330 knots go ahead nobody stopping you. Use what you feel is right.I on the other hand have no issues with a cost index of 36 which gives me 280 knot descent rates at 1800 to 2200 fpm and makes it easy to slow down anytime I need to.

[Spin737 102]

Cost index has nothing to do with high idle. This thread started with high idle problems. It doesn't matter what KhazakhDiscountAirExpress uses for CI.

[Paul Deemer 13]

Cost index has nothing to do with high idle. This thread started with high idle problems. It doesn't matter what KhazakhDiscountAirExpress uses for CI.

Yeah your right but some how the thread changed over to cost index so I took it from there. As far as the idle goes Ops idle is a bit too high so definately an issue. At 9000 feet descending into TNCM right now my idle is at 34 percent.

[davierosoft 13]

I just made a little test with idle control... and probably found something, something I normally cannot see as I don't use anti ice.First of all, I must say that I actually don't have the slow down issue, but, now I can replicate a thing, I will try to see if I can replicate the slow down issue.I tried using LVL CHG descent,Wing Anti ice was off.Trottles were at idle,N1 about 32% I think.AT mode ARMTurned on wing and eng AIN1 increased to 37-39% (as expected)Throttles advanced a bit to rise the idle (idle control doesn't use throttles)AT mode was still in ARM (and in this mode the AT cannot move the levers)Turned back OFF the wing and ENG AIN1 remained t the last position (37-39%)Throttles remained at the previous position as the throttles in ARM are not able to move themBy moving the controller throttle the idle returned to its nominal value.I'm just remembering a very old post about this I think.So, imagine:You used the AI for part of the descent, you turned it off, your idle is now not restored and the aircraft will be not able to slow down normally until you move throttles manually or AT mode changes.This does not mean I found the issue, as I don't use AI and didn't also wen I had problems, but found another one.I'll post a short video soon

[Superpilotv2 2]

All right, Thanks for this Test. I won't use anti ice for this flight. Cruising at FL260 towards Fairchild intl with M. 0.72. Take off was no problem and I've everything correctly configured for app. Also the DES FORCAST is filled out. Let's hope everything goes well. I'll observe the engines on app and report back.

[rocketfs 2]

I just tested this too and indeed, N1 stays high (38%) after switching off TAI. When switching from LVL CHG to V/S and back to LVL CHG, the engine idle N1 drops again to about 31%.Bug or feature? (not sarcastic here)Also, the FCTM and FCOM1 clearly indicates that when using TAI, you have to put that in the FMC DESC FORECAST page.Bert Van Bulck