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Posts posted by Finn

  1. If MSFS2020 Fuel system is like in FSX/P3D, then You cannot transfer fuel between tanks.

    Actually both the electrical and fuel system of MSFS2020 (actually taken from FSX) is very limited in what You can do with them.


    Well a couple of "special" tanks can transfer fuel between them, but these stems back from the FS2000 Concorde and cannot be used in a regular way.

  2. The Twin Otter has two low pressure pumps for each Tank (FWD & AFT).

    FWD Boost pump 1 & 2

    AFT Boost pump 1 & 2.

    Only pump 1 OR 2 for each Tank normally runs, the other will be on standby, should the other fail.

    Additionally each Engine has it´s own high pressure fuel pump.


    Here is how these pumps operate in the real Twin Otter:


    Each Boost pump has a caution light.

    Each light is energized by a pressure switch in the delivery line of the corresponding boost pump if the fuel pressure downstrean of the pump falls below 2 Psi.

    In normal operation the pressure from the No. 1 boost pump in each tank actuates the No.1 pressureswitch, which extinguishes the No.1 Boost pressure caution light.

    It also renders the No.2 boost pump and the No. 2 boost pressure caution light inoperative.

    Should the No.1 boost pump fail, and thus the No.1 fuel pressure switch activates (No. 1 Boost pressure caution light will illuminate) due to low fuel pressure, this will turn on the No.2 boost pump automatically.

    Should this not happen automatically it can be done by switching the STBY BOOST PUMP EMER switch from NORM to Up position.


    Boost pump 1 FWD is powered by the Left DC bus and feeds the Right engine

    Boost pump 2 FWD is powered by the Right DC bus and feeds the Right engine

    Boost pump 1 AFT is powered by the Left DC bus and feeds the Left engine

    Boost pump 2 AFT is powered by the Right DC bus and feeds the Left engine



    Boost pump 2 (FWD/AFT) will only activate if Boost pump 1 (FWD/AFT) fails, or the STBY BOOST PUMP EMER switch is in the up position, or the Boost pump switch is set to TEST (springloaded).


    The Engines though can run on their High pressure fuel pump alone i.e none of the low pressure fuel pumps runs, but it is not allowed.

    At least one low pressure fuel pump must run per Tank, and this only up to 8000 ft.


    It has been reported that the Engines has been able to run without the low pressure pumps up to 16.000 ft.


    So it isn´t unrealistic if the Engines keep running without the low pressure pumps running below 16.000 ft.

    But above 16.000 the engines will quit.


    The altitude is only approximatly, and depends on air pressure, temperature etc..






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  3. I concur if it´s really necessry to reduce the numbers of animation, then leaving them in feathered position is better.


    But next question is - are the develpers really so limited that this has to be done ?

    As far as I know, the Twin Otter for MSFS2020 does not have anything that can be called an excessive number of animations.

    There aren't that many switches, levers or gauges to animate, so if they allready has hit the upper limit, then MSFS2020 / Xbox is way too limited and Xbox should never has been considered as being a platform for a Flight Simulator.

    But let´s see what will happen.


    A fix seems to be on the way for the PMDG DC-6 Xbox version, so maybe it´s a matter of fixing the Xbox, rather than restricting MSFS2020.

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  4. Basicly the start locks do the same as keeping the propeller blades  in the beta range.


    The problem with the PT6 engines and propellers without start locks, is that when the engines are shut down, the propellers feathers.

    During the startup, the propellers unfeathers and thus moves from feathered position, through the course  (low rpm) range to full fine, but still not in the beta range.

    During this the propellers produces forward thrust.


    The start locks prevents the propeller blades to feather during engine shutdown and actually keeps them in the beta range, where they don´t produce any thrust.

    To set the start locks, the power levers will be moved into beta range before shutting the engines down with the condition lever.


    To unlock the start locksm the power lver has to be moved into beta range after engine start, otherwise the engines will simply speed up without producing thrust when the power levers are moved forward.


    The start locks does not need to be engaged if the float / amphibian is moored, therefore You can find vidoes of Twin Otter float planes where the startlocks not has been engaged.

    I guess it´s better to start a free turbine with the propellers feathered, since the spin up of the propeller will be slower dur to the mucj higher drag of the feathered propeller.





  5. I use FSUIPC for my Engine Levers.

    Doing so, I can set ithe Power levers to both cover the normal range as well as the revers range and thus set the Propellers into what is regarded as the Beta range i.e no forward or reverse thrsut.

    Also my Prop levers cover the entire range from full fin back to feathered position.


    I´m sure You can do the same with the TCA throttle.

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  6. MOve the Power levers into Beta range.


    Note most Twin Otters with Floats or amphibian has so called startlocks installed.


    Normally when stopping the Engines, the Propeller blades will move into feathered position.

    The problem with Float and Amphibious aircraft is, that when starting the Engines, the Propeller unfeathers and cause them to surge the Aircraft forward - You don´t have any parking brake :)


    With Startlocks installed, You moVe the Power levers into Beta range before shutting down.

    When shut down, the Startlocks prevent the Propeller blades to move and they stay in full flat position.

    So the next time You start the Engines, the Propeller do not produce any thrust.


    This was simulated on the Twin Otter Extended, but I´m unsure whether this has been implementet on the MSFS2020 version.

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  7. You can download the PMS 530 here: Release v1.0.46 · pimarc/pms50-gns530 · GitHub


    With this installed the current GPS in the Twin Otter will be upgraded to a state much closer to the real thing.

    It also included the 430


    Main features

    • MSFS U-turn bug workaround
    • North Up / Track up map modes
    • Terrain Map
    • Map cursor with waypoint selection
    • TCAS (anti collision system)
    • NEXTRAD weather data
    • Better DirectTo management
    • Weather radar
    • Wind indicator
    • VNAV page
    • Dynamic flight plan distances
    • Flight plan catalog and flight plan import
    • Procedure maps
    • METAR (with decoded option)
    • GNS430 included
    • State saved between sessions
    • Message management
    • Configuration file
    • Startup screen
    • Many graphical enhancements
    • Night/day lighting
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  8. 1 hour ago, abennett said:

    I do not know comfortable Aerosoft are with people tweaking their cfg's so I am reluctant to post it here, but you can check on the official forums https://forums.flightsimulator.com/t/aerosoft-twin-otter-baby/395128. This post has all the info. I am glad a persevered rather listened to those telling me user error and read the manual. I know what I am doing, been doing it for years.

    Wow - using the Kodiak values fixed the VS behaviour for me.

    Now it keeps VS regardless (Well not below stall speed offcourse) at what speed I fly and captures the altitude just fine and smooth.

  9. The Dolls eyes are the two black squares on each side of the Torque Gauges.

    Right now the Inertial seperators are not implementet in the MSFS2020 version.


    But see the explanation here for the Aerosoft Twin Otter Extended (FSX/P3D):


    The inertial seperator consist of an inlet deflector plate in conjunction with an exit duct door that can be moved with a pneumatical actuator.The exit duct door opens when the delfector extends.


    When the deflextor is extended the air will be deflected towards a a fine mesh screen at the upswept end of the inlet duct. While the air can pass the mesh, debris and ice will be deflected out of the exit duct door togehter with some of the inelt air.


    With the deflector plate retracted and the exit duct door closed all air will be lead to the intake.


    Thats why the engine will produce less power with the deflectorplate extended.


    To extend/retract the inertial seperator the switch must be held until the pneumatic actuator has fully moved the plate and the "Dollseyes" in the main panel will indicate "Blank" or "EXT" (Two square items on each side of the torque gauges). The Dollseyes are alo pneumatical.


    They are called Dollseyes cause they open/closes in the same way as Dolls eyes.


    I think I have seen photos where bothe the text RET and EXT are used (RET instead of Blank).



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  10. 8 hours ago, abennett said:

    How does it automatically engage ALT mode when approaching selected altitude if there is no ARM function? How does every other aircraft manage to not shoot through selected altitude?


    On other aircraft with this system, you can also pre-select a VS so that when the AP is engaged it doesn't go to 0 fpm in the climb, pitching down, ruining the trim and airspeed. How is this possible with the same system but not here?


    Genuine questions, look I love the Twin Otter, I flew your version in P3D for hours and hours and hours and hours. I just want this one to work, I am happy to test and test and test, it is mainly all I've done for the last two days anyway along with a friend who has the same issues. I just want it to work.

    Because Asobo desgined it to always ARM.


    I´m sure some parameters can be adjusted for the Autopilot ins the System.cfg, I´m just not sure which affects the KAP140 and where to tweak.


    But You are right...

    The correct functions for the KAp140 is described here: https://www.touringmachine.com/PDFs-Txt/Cessna172/KAP140 Autopilot Quick Reference Card.pdf

    But this is not how the current KAP140 works - unfortunatly.


    If You know a MSFS2020 aircraft,that uses the KAP140, which works more correctly - please tell.

    Maybe some of the settings can be "borroughed" from that then.


    I agree that the AP currently is a hit or miss affair and quite unreliable.

  11. Not sure if they work, but look at this link for Sim events:






    Even Autofeather Arm is  there, if it they wanted to implement that like in the Twin Otter Extended:



    I think at least the Autofeather light should come on when Autofeather switach has been selected - kind of what You would see during a normal Take Off / GA.

  12. 2 minutes ago, dresoccer4 said:


    ok so it is the asbobo autopilot. from my experiments in other planes, it seems unable to provide enough elevator trim authority for some reason when you decrease power. 

    I was able to keep the Twotter lower than 120kts by keeping her in altitude hold until I was around 100kts and then slowly decreasing the VS fpm. It seemed to work decent enough then. The problem seems to be exacerbated by lowering your power setting while it's already in a descent mode and it won't compensate.


    These are just my observations.

    Yeah I also asume that the Asobo KAP140 has problems with having enough Elevator authority.

  13. When using VS mode, keep airspeed in the range 120-140 kts, below or above seem to give the KAP140 autopilot problems.

    The KAP140 is the default Asobo Autopilot.


    Maybe some tweaking of it's settigs in the systems.cfg could help it, but it´s known for having issues.

  14. Try to keep the speed between 120-140 kts.

    Seems the Asobo KAP140 has problems when flying too fast or too slow.


    The same, just opposit, happens when climbing in VS mode. Once You get beyond 140, climb rate starts to increase above the VS setting.

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