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PostPosted: Thu Sep 06, 2012 10:35 am 
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The "Introducing the Albatros D.III (Oeffag) for Microsoft FS" thread started to go a little off-topic with my comment about rudder authority:
viewtopic.php?f=100&t=31509#p240027

Let this be the continuation thread of the things that could possibly be improved on. After all, that announcement thread (like all announcement threads) are in a "limbo", i.e as it's not located anywhere on the forums, it can only be accessed via direct link after it expires (so use the above link to access it when it disappears from universal hot topic announcements).

Also, in copy-paste the solution to propeller inertia here:
whiic wrote:
Here's the solution to propeller inertia:

aircraft.cfg:
Code:
// propeller_moi =16.25720
propeller_moi =6.50000


It's only approximate. Tweaking it about +/- 0.2 from 6.5 could give better. The catch however is, the propeller_moi setting would give a matched spindown of the prop only for a fixed idle rpm. 6.5 is good for 600 rpm (0% throttle) and 660 rpm (5% throttle as recommended by the manual for shutdown). If engine is run at 500rpm (0% throttle on a cold engine, and shut down before it starts to run properly) the sound sample will continue to run after prop has stopped. Well, without Core Accusim, this is the FSX engine sound modeling. 6.5 could be a good value, give or take 0.2.

For those too impatient to wait for an official update - make a back-up copy of your aircraft.cfg before attempting ANY changes to it, no matter how small (same applies to people who add repaints). While changing propeller_moi (especially if you comment the old value with "//"s to back-up it) won't break much, accidentally deleting a paragraph or two would. Totally unintended mishaps do occur. Therefore back-up the entire file before editing it.


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PostPosted: Thu Sep 06, 2012 11:47 am 
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Much appreciated, Whiic! Thanks!

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PostPosted: Mon Sep 10, 2012 4:48 pm 
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I didn't notice it immediately while tweaking propeller_MOI to it's proper value but you can't start the plane after propeller_MOI fix... unless you also adjust normalized_starter_torque. It managed to slip my testing because to save time during multiple iterations for correct propeller_MOI, I cheated using engine autostart hotkey.

What caused the problem to occur after fixing prop inertia?
When you decrease propeller_MOI to around one third of the original to fix the excess inertia of the prop, it will also make the starter torque to drop 2/3 down from it's original value since it's normalized to the inertia. Reducing propeller_MOI doesn't however reduce engine friction and prop drag - otherwise decreasing propeller_MOI wouldn't let the prop to stop faster after shutdown. The same friction that remained constant despite reduction of starter torque to 1/3 of original will cause the engine to not reach high enough rpm to catch.

Another fix is required, for example:
Code:
// normalized_starter_torque =0.19232
normalized_starter_torque =0.3


It's only a minor increase for normalized starter torque but it seems to do the trick.

Sorry about posting an incomplete fix that created a bigger bug while solving another. I hope after this fix, there won't be any other unfixed ones.


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PostPosted: Mon Sep 10, 2012 5:12 pm 
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Works perfect! I remember a similar problem with the Bf 109 Solo after the FSX patch. I had to increase this parameter as well, to be able to start the engine from the cockpit.

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