Wrong entry in Flight_model.cfg

I found that in the Flight_model.cfg of many aircraft there is an entry

drag_coef_zero_lift_mach_tab

I think it should instead read

drag_coef_zero_lift_mach_table (as it’s in the SDK)

Also many 3rd party aircraft have it. This entry is shown as required in the SDK.

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Good catch. Given that most (all?) other tables in the file indeed have names that end with _table, it does seem plausible. Did you report this on the devsupport site? One usually does get replies to technical questions there.

No, not yet.

For the C208 this table looks like that:

So, either this is some legecy stuff (but would it be in the SDK then? Even as required?) or it is spelled incorrectly.

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BTW, what tool do you use to turn a table into a graph like that? I assume it is bi-directional?

Yes, it is.

Hmm, OK. Not sure I want to use such a tool, though, if it (just like Dev Mode does, if you use it to tweak settings) rewrites the whole .cfg files. I tend to edit my .cfg files by hand, to be able to keep them clean and easy to read, with nice vertical alignment, with lots of extra commentary, etc. I even use a macro processor to be able to for instance use inches for measurements from the aircraft’s documentation in the source, and the macro processor translates that to the feet that MSFS wants, and to be able to split tables into one line per table row;)

I mean, like this, for a part of my flight_model.cfg that is just boilerplate values still from I think the DA62 sample:

yaw_moment_delta_rudder = 0.98642                 ; Change in yaw moment per change in rudder deflection (primary yaw power factor) C_n_delta_r
yaw_moment_delta_rudder_propwash = 0.2466         ; C_n_delta_r^propwash
yaw_moment_delta_rudder_trim_scalar = 0.98642     ; Change in yaw moment due to rudder trim C_n_delta_rt
;
compute_aero_center = 0                           ; Whether to compute aerocenter from lift and pitch moment AoA curves (BOOL)
aero_center_lift = POZZZ(140)                     ; Longitudinal position z_CoL of the center of lift (only active if compute_aero_center = 0)
;
; Lift function of AoA table. Influence CoL computation if not prescribed and stall angle computation (stall angle = angle for which this table reaches
; its maximum value) C_L_alpha(alpha)
;
lift_coef_aoa_table = ONELINE(<<
    -3.15 :  0,
    -0.8  : -1.231,
    -0.4  : -0.917,
    -0.2  : -0.772,
    -0.1  : -0.246,
     0    :  0.3,
     0.2  :  1.118,
     0.23 :  1.183,
     0.26 :  1.231,
     0.29 :  1.224,
     0.31 :  1.071,
     0.4  :  0.917,
     0.8  :  1.24,
     3.15 :  0
>>)

But sure, I see the usefulness of a GUI tool to edit tables (i.e. curves). I just don’t want it to do too much…

You could still use it to edit tables and then copy the new value to your formatted .cfg file. Or just use it for consistency checks.

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The typo appears to be in the SDK (and the coding). I just ran a quickie test. Changing the values in the drag_coef_zero_lift_mach_tab results in changing the drag coefficient for a given condition. Changing the table name to drag_coef_zero_lift_mach_table and changing the values in that table does not result in a change to the drag coefficient for a given condition.

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Thanks. That means the “typo” is not only in the SDK but also in the source code of the sim.

What tipped you off to this conclusion? How is it also wrong in the source code of the sim?

Spelled as _tab it works, so how could it be wrong in the source code?

“Wrong” in the sense “differs from documentation”. But if nothing else is done, it is the documentation that needs to be fixed to match the source code, of course.

(Or ideally, the documentation should keep using the consistent fully spelled out name, and the code should be changed to accept either spelling, in order to maintain backward compatibility with flight_model.cfg files that use the typo, while the files in the samples and bundled aircraft should be fixed to spell “table” out fully.)

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Ok, that’s what had me confused. Only one could be wrong. But, I agree, consistent naming is really important in my book.

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Another one:

In some default aircraft the entry ignition_auto_type in section [TURBINEENGINEDATA] has values that, if you read the SDK, are wrong. The SDK states:

Integer:
0 = Always on
1 = Ignition follows starter status
2 = Ignition enabled when Flaps are not neutral, when AntiIce is enabled, or when N1/N2 is below 50%.

The default aircraft have various entries like:

ignition_auto_type = “Starter”
ignition_auto_type = “AntiIce,Flaps”
ignition_auto_type = “Starter,Flaps,AntiIce”
ignition_auto_type = “0”
ignition_auto_type=""

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