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DTG Martin

Help us squash FSX bugs once and for all (Official)

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Some of you may already know that Dovetail Games Flight Simulator is based on an updated version of the FSX engine . As part of continued development, one of our top priorities is addressing known bugs and glitches.




No one knows more about this complex simulator than you, the flight simulation community, which is why we want your help identifying these bugs and glitches so we can build a more stable simulator.  




When we say “bugs and glitches” what we mean are processes within FSX which do not function as they should. We do not mean features that you would like to see in a simulator.




In order to tackle these bugs, we need reproduction steps from you, or a list of instructions which results in the bug or glitch occurring.


For example:



  1. Click menu item A


  2. Select Aircraft B


  3. Once the game loads fly from C to D


  4. And so on

Please post these along with any other information you deem useful in the comments section below. We understand that it is not always possible to communicate repo steps for every single bug or glitch. In such cases, it would be helpful if you could provide as many details as possible along with a description of what you were doing in the simulator when the error occurred.



We want to thank you for being such a helpful and engaged community, and look forward to hearing from you.



-DTG Flight Simulator Team


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There are a couple bugs I think definitely needs addressing.

One of them is the UTC Time bug. The main problem with it is that when crossing timezones, the UTC Time is changed rather than local time. I believe I mentioned this in the Options topic but this is also a major bug that I have to bring this up. For example, if you fly from Chicago (UTC -6/-5) to Indianapolis (UTC -5/-4), you would end up flying into daylight. This also applies if you fly from Portugal (UTC 0/+1) to Spain (UTC +1/+2). There are also some cases where timezones are wrong or Daylight Savings are at the wrong dates. Currently to solve these issues, a utility called FS Real Time was used. Like before, I did mention this in the Options topic about UTC. To reproduce this, any aircraft will do and in Dusk times flying East (Portugal to Spain or Chicago to Indianapolis would be good enough).

Another problem to mention is that if you fly near the equator and do a 360, the camera shifts more often than normal. This is more noticable in larger aircraft (Boeing 747 and the 777 comes to mind). Reproducing this is easy. All you have to do is use a large aircraft like the 747, anywhere in the world would do as long as it's near the equator and in any time of the day.


Speaking of equator, any form of texture that is in the equator and the poles (clouds are included) appears distorted. I might have to be technical on this for the textures but in latitudes where most consumers live in (North America, Europe, Japan, Australia and New Zealand), textures are nearly a perfect square. But in areas close to the equator or the poles, the textures are no longer squares making them distorted. As for the clouds, Active Sky 2016 managed to fix this issue. Again, very easy to reproduce, anywhere near the equator or the poles (I recommend the poles first), any aircraft will do and so is any time of day.


I also like to mention another fault with FSX and it is how it loads or dumps scenery. I know this is a 64-bit program (it was mentioned a couple of times since early this year) but I feel there would be less problems if this issue is sorted out. FSX isn't that good with dumping scenery that you flew over and at the same time, it even loads scenery that you're nowhere near, even on the other side of the globe. Basically, scenery souldn't be loaded 200nm/370km (or less) away from the aircraft and (if already loaded) should be dumped completely if they are that far from the aircraft. Using addon scenery (including airports), enabling and disabling them should be enough to reproduce.


Finally, there is the ground friction bug where the aircraft decelerates quicker than it should on the ground. Since this is a physics issue, this can be reproduced by any default aircraft (I suggest the default Cessna) in any airport (one with a concrete or asphalt runway) and taxi in the runway at 50 knots. Then set the thrust to idle. In real life, the Cessna should stop somewhere around the end of the runway but in FSX, it stops in a couple of meters.

Edited by n4gix
Added paragraph breaks to improve readability.

Júnior Silva

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I would add:


- The old Leaning Bug, whereby when you start leaning a reciprocating engine and you're above 3000', but it is more noticeable the higher you fly, the fuel flow starts increasing, and only after a while behaves again as supposed, starting do reduce, as it should right from the moment you start leaning;


- The poor modeling of turboprop engines, where there is no beta range modeling;


- The poor modeling of turbprop engines with a free-runing turbine, like the PT-6 that exhibit variations in Fuel Flow ( FF ) when, for fixed throttle and condition settings you make adjustments to the Prop RPM;


- The poor modeling of the "Turn Coordinator" where you can seldom perform a standard rate turn for a given aircraft equipped with a TC and 2 min or other time, marks, taking 2 minutes to complete a full 360º ( or 4 min in case of heavier aircraft or 1 min in case of most gliders );


- On page 38 of this EXCELLENT source of information by Yves ( available from the AVSIM Library ) you can read about "roll moment due to torque":


"The roll effect is at its maximum at zero airspeed. It decreases linearly with airspeed (TAS) and becomes zero at flaps_up_stall_speed (TAS) from [reference Speeds] multiplied by 1.5. The effect remains zero above that speed."


meaning that in FSX's internal flight dynamics model torque no longer exists once your prop aircraft reaches 1.5 * TAS(flaps_up_stall_speed)... I believe the same applies to slipstream effects on the tail surfaces, specially after the step from fs9 to fsx which erased at least one important internal variable. 

Flight Simulation is the Virtual Materialization of a Dream...

Uninstalling flightsims is a temptation I can never resist...



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I forgot to mention this. There is a problem with Jetways where if the aircraft is lower or higher than the jetway, the wheels sink or rise midair just to get to the door. Any aircraft where the main door is not the same height as the jetway would do and in any airport with a jetway. Time of day doesn't inflence this.

Júnior Silva

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It would be nice if the new globe was indeed a sphere, i.e., you can't reach the poles NPole/SPole in FSX.


Being able to navigate around the earth without restrictions is a very basic demand but a long lasting bug...

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Bug: FSX requires carb heat in fuel injected engines


Bug: FSX requires fuel mixture set full rich to start up a jet engine


Bug: FSX scans its default scenery folders at startup to find airport elevations and navigation data, completely ignoring the layer ordering in scenery.cfg. This prevents an addon scenery from changing airport elevation unless it puts a file into the Scenery\World\Scenery folder, which breaks modularity and the ability to enable/disable sceneries properly via the scenery library interface


In addition, autogen configuration and terrain config entries can only be added by modifying global files which breaks scenery modularity. Sceneries should be able to include their own autogen config and terrain configs within the scenery folder structure without hacking global files.

  • Upvote 1

Barry Friedman

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These are great. Please keep them coming everyone. 


- Martin 

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FSX has a sound problem. When going to outside view and then back to cockpit view, the sound changes (you loose sound files or it adds them). Pressing 'Q' twice in most cases restores the correct sound files.

Menno C. Robert

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Mouse bug: When flying in Virtual Cockpit, having the mouse cursor on the screen results in a significant loss of FPS. (I did read an explanation for it here on the forums and tough I do not recall the specifics it should be easy to solve as far as I remember)

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- utc time
- flickering



- popping

- ctd

- problem with sound pressing the key (Q)

- wave ship

squares in the sea

- objects sinking into the ground
- to activate the scenarios, first you need to press on the white space.

- Viewpoint. I want the view blocked in virtual cockpit, many planes pay the view moves.




 Lorenzo Guidotti

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Blank Atc menu after ATC instructions. You need to switch frequencies to bring back the menu.


when Running FSX in fullscreen mode, switching to another application like music player, then switching back to FSX is a real pain. You have to use the maximize feature of task manager to bring back FSX into focus (win10). It's been fixed in P3D.

Onela Pivra


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Difficult  to properly adjust brake pedals. No matter the brand of pedal seems there is always an issue with brakes grabbing or spiking.

Vic green

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I'm not sure if this is a bug or a nitpick but for the radios, when controlling the nobs, there is difficulty with moving the digits back. Some people use the mouse wheel for adjusting radio frequencies. I prefer it if it is designed so that when scrolling up moves the digits forward while scrolling down moves the digits back. Others may use left and right mouse buttons to adjust radio frequencies. In this case, left mouse button should move digits back while right mouse button should move digits forward. I wasn't sure whether to include this but I felt it might be better to do so.

I don't know if this is fixed but there is an issue where in FSX, when hovering the mouse in the Virtual Cockpit may cause lower FPS. I remember PMDG mention something about it years ago. The reason why the low FPS happen is because FSX didn't have something called a Hardware Cursor. A Hardware Cursor in 3D Games have the cursor as a 3D object, meaning that there isn't much of a performance hit since it's already in the 3D engine. Without a Hardware Cursor, the CPU has to work harder to figure out where in the 3D Space the mouse is referring to since the mouse is a 2D Windows object overlayed in the sim's 3D engine. Aces was going to add a Hardware Cursor to sort out the problem in SP3 but they were closed down before this was possible. This may be a feature but the performance issue when using the cursor is something I couldn't ignore and felt like putting in. This is the post I'm referring to: http://www.avsim.com/topic/341886-fps-drop-when-mouse-cursor-visible/?p=2047611

Júnior Silva

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FSX has a sound problem. When going to outside view and then back to cockpit view, the sound changes (you loose sound files or it adds them). Pressing 'Q' twice in most cases restores the correct sound files.



It's not a bug, but having sim retain its sound when it's not "in focus" would be great. Currently, you can buy Flight 1's SoundStream to gain this capability. Unfortunately, said tool doesn't work in FSX SE...

Matt King

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