New prop coefficients

There are a couple of new parameters in the engines.cfg file which I can’t
find description in the SDK for. And looking at their names I am at lost to
understand what effect they have on the flight model. Namely, these ones:
prop_effmaxsmooth = prop_effminval = prop_scalepowerabs = (scalar on power
absorbed by the prop?)
prop_falloffcoef = prop_falloffpower =
prop_lowbetareduction = prop_lowbetareductionmid =
advance_ratio_on_effective_beta = I would be most grateful if anyone could
give an explanation.

Hello. Actually, these are documented in the latest version of the doc. Try to
clear your cache and if that’s not enough, use a private navigation tab to
access the doc. You can also check the .chm provided with the SDK. Regards,

Sylvain, Thanks, I have found them in the new version. But a bit more
elaborate description would be welcome. For example:

This is the factor of the advance ratio on the effective beta.

This description is, in essence, a reiteration of the name of the variable.
However it’s unclear how it affects the behaviour of the prop in the sim. It’s
a bit clearer about the other parameters, but I’m puzzled about how I can
affect the prop thrust efficiency in the lower part of the prop efficiency
curve. From the descriptions they mostly affect the upper range of it. Ilya

Hello! That parameter WAS basically an indicator of the prop effectiveness at
producing thrust depending on the flight conditions. It was used to tune the
effect of the advance ratio on the propeller’s beta effectiveness at producing
thrust… HOWEVER: For legacy aircraft this has been replaced by the table
prop_power_cf, or is internally calculated by the engine when using the modern
flight model. The next update will flag the parameter as no longer used by the