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NG % RPM values always high

Scheduled Pinned Locked Moved Piston & Turbine Dukes
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  • C Offline
    C Offline
    Captain_J
    wrote on last edited by
    #1

    I've setup a variety of different 'correct' cruise power settings, but my NG % RPM is constantly sitting just over 100 and therefore just into the red ... seems awfully high to me. But, I just don't know how to get it down without reducing the torque so much I start to run out of speed. What am I missing? Thanks, John.

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  • Black SquareB Offline
    Black SquareB Offline
    Black Square Black Square Developer
    wrote on last edited by
    #2

    The gas generator's redline is actually 101.5%, so unless the engine monitor is alerting you to a high Ng, you're probably still under the limit. If memory serves, you should not have to concern yourself with high Ng during normal operations in the Duke until very low ambient temperatures.

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  • C Offline
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    Captain_J
    wrote on last edited by
    #3

    OK thanks, I hadn't realised that. So maintaining around 101.2 for the entire time is OK then?

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  • Black SquareB Offline
    Black SquareB Offline
    Black Square Black Square Developer
    wrote on last edited by
    #4

    That should be completely acceptable. The gas generator limitations are specified in the Engine Limitations section of the manual, as follows: 101.5% (Continuous) 102.6% (Momentary) 101.5% (Reverse)

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  • C Offline
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    Captain_J
    wrote on last edited by
    #5

    Thanks again, kind regards John.

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  • T Offline
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    ThargorV8
    wrote on last edited by
    #6

    I still wonder about the NG/Torque curves in both the TBM and Duke myself. After the 1.2 TBM changes and the Duke from launch, I generally have to run right at the NG limits at cruise to get any speed out of either aircraft. Most of my turboprops generate the last 40% of torque over 10-18% of NG while the Duke and TBM generate 40% of torque over only 2-3% of NG. Every other turboprop (including the BS Caravan and BS King Air) I own has a fairly linear torque curve vs NG except the TBM and Duke which have a flatter curve up to around NG and then go exponential.
    The NG I have to use in the sim for the TBM also does not seem to align with what I've seen in online videos of an 850 where the real plane seems to be able to generate the same torque at lower NG values than the TBM after the 1.2 update.
    I'm curious if the Caravan and KA updates are going to come with the same NG/Torque changes where they will have most of the torque generated in the last few %NG?

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  • C Offline
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    Captain_J
    wrote on last edited by
    #7

    Interesting comments you make - now I'm a little confused as to how the Duke Turbine would perform in real life in respect to the above???

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  • T Offline
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    ThargorV8
    wrote on last edited by
    #8

    On a Flight Sim site I asked a while back about anyone with real world experience with the PT6 and knowledge of real world Ng vs Torque curves but even the people that fly PT6 aircraft didn't know or never paid attention to it.

    I've spent a fair amount of time in King Airs for the company I work for but only as a passenger. I may ask our pilots if any of them know. I have some real world experience but only in piston aircraft.

    I do watch a lot of videos online of turboprop aircraft but all I've been able to glean is short shots, usually at cruise; and I've never seen a Turbine Duke online for comparison. I used to fly/sim the old RealAir Turbine Duke but I don't recall the cruise NG/Torque values.

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  • C Offline
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    Captain_J
    wrote on last edited by
    #9

    Hey thanks - yep, I'd certainly appreciate any further info. you're able to provide, thanks :).

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