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avhpilot

thrust IDLE still going 30/40% N1

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I have noticed that after engine start, idle thrust will produce approx. 20%N1 I have noticed that on a descent, whehter it be via VNAV or LVL/CHG or V/S, when the throttles are pulled back to "0" the engines still produce 30 to 40 % N1. When disarming AT and CMD switched off, it is still impossible to reduce to about 20%N1. I notice that when clicking on the F1 button it attempts to reduce thrust but it will be immediately overruled. Question, Is this the way the aircraft behaves while in the air?Has this something to do with GoAround mode which requires a min of thrust? i have noticed this behavior with the indication CRZ on the upper DU as well though. I'm NOT using anti-ice, so that cannot account for the extra thrust. I am using Saitek Pro Yoke and throttles, Axis configured via FSX, not via my registered version of FSUIPC Any ideas?


Antoine v Heck
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i7 980x, 12Gb RAM, Asus P6T deluxe V2 MB, GPU 780GTX (6GB VRAM). 500GB SSD drive, FSX Steam Edition + Xplane10.5 + XP11pb

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this is called 'flight idle' (in contrast to 'ground idle') and depends, as far as i know, on numerous factors. So this totally normalregards,christopher volle


Regards,
Chris Volle

i7700k @ 4,7, 32gb ram, Win10, MSI GTX1070.

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Sure this is because on the ground you have very limit wind acting on the N1 blades. Now in flight and decent you have more airflow moving over the blades even if you idle in decent as your moving few hundred knots as the planes moves though the air. I'm not 100% but it sounds to be the case.


-Raven Harris
Intel i7 980X @ 4.43GHz | ASUS Rampage III | Corsair 6GB DDR3 2000MHz | 3 EVGA GTX280 | Corsair 1200 Watt | Intel 510 SSD (RAID 0)
PMDG - 747-400/8iF | MD11/F | BAe J41 | 737NG 6/7/8/9 Hope ER/BBJ|777LR/F
Flight1- Cessna Mustang

 

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And if the effects continues after landing, as I have experienced? The only way I have found to overcome this is to reengage and then disengage the A/T during taxiing


// Lasse Kronborg

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Sure this is because on the ground you have very limit wind acting on the N1 blades. Now in flight and decent you have more airflow moving over the blades even if you idle in decent as your moving few hundred knots as the planes moves though the air. I'm not 100% but it sounds to be the case.
OK, thanks for the clarification. Next question: has this been modelled in other hight quality add-ons like LD767, PMDGs 747x, MD11. i suppose it has ... but why am i only noticing it now in the NGX i wonder.

Antoine v Heck
---
i7 980x, 12Gb RAM, Asus P6T deluxe V2 MB, GPU 780GTX (6GB VRAM). 500GB SSD drive, FSX Steam Edition + Xplane10.5 + XP11pb

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The EEC should go from flight Idle to ground Idle, about 4 seconds after touchdown.....
It doesn't in my case. I have been taxiing all the way to the gate using high idle

// Lasse Kronborg

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Maybe try something: at departure, on ground, at the gate, push your throttle joystick forward, and then put it back to minimum: does it come back to ground / minimum idle or not ? I had that problem in the past, and it was a joystick calibration problem, further to an add-on install that made a complete mess in it.


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this is called 'flight idle' (in contrast to 'ground idle') and depends, as far as i know, on numerous factors. So this totally normalregards,christopher volle
one reason for this is also to ensure that the engine driven generators are capable of producing sufficient electrical current whilst in flight, pulling all the way back to full idle would mess up electrical generation

 

- Jane Whittaker

 

 

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one reason for this is also to ensure that the engine driven generators are capable of producing sufficient electrical current whilst in flight, pulling all the way back to full idle would mess up electrical generation
They should do the same on ground, but they don't (58% N2 minimum IIRC). Try cold OATs and see yourself. sig.gif

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Only below 15,500'. Same goes for flaps. Not so for TAI though. This is modelled correctly BTW. sig.gif

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