Request: Use legacy flight model features

Is it possible to allow us to activate legacy flight model tables using cfg
entries, similar to what you did with the engines (prop_uselegacytables). This
way we can use the old FM tables as needed to exert fine control over the
aircraft. Of course, people who choose not to use these toggles will be able
to work as usual.

I agree totally with this - I have commented in another thread here in a
similar vein. The modern flight model allows us to define a cylindrical
fuselage and very basic wings, the geometry base is not accurate enough to
deal with the more unusual shapes which define fairly common aircraft. The
main criticism of the FSX flight model was that it ran on rails. The root
cause of that was that all of the coefficients were acting upon one point. The
modern flight model gets around that issue, but it is not accurately defined
enough to give the best possible results. I would like to see the core FM seen
as a ‘skeleton’, it gives the most basic shape but allows forces to be defined
across it. Putting the entire, fully accessible and working FSX FM on top of
this, with the default setting for all tables and coefficients being =1 (i.e.
the core FM is unchanged, so previous in-house and 3rd party add ons should
not need adjustment) leaves people free to continue developing using just the
core FM. However, it also allows experienced users to really flesh out the
aircraft around that core skeleton and potentially create something which I
think would match and possibly exceed the original aims of the sim’s creators.

Honestly I think this is unlikely to happen. What we will (and in some cases
already) see is the new flight model fleshed out even further with more and
more options that are designed specifically for the new model instead of shoe-
horning the old FM onto it. We have, with SU6 seen quite a few new additions
added to engines that will allow us to add more precise controls over them
with multi stage superchargers, pressure regulators etc etc. We feel the pain
now because, right or wrong, this new model is still in its infancy and can’t
do everything that we’re used to doing in the older version. I honeslty
believe that will come in time and that time will never arrive fast enough ;')

We would also like to see the legacy flight model be selectable via a
flight_model.cfg entry, rather than having to ask the user to switch to it by
hand. Unless you plan to remove the legacy model altogether in the future,
please bring this switch to flight_model.cfg. Thanks!

Just to clarify- the ability to enter

use_modern_fm = 1

is already there for flight_model.cfg - We would really appreciate its
counterpart to exist:

use_legacy_fm = 1

That would make our lives much much easier - could you please let us know if
that’s a possibility? Thank you in advance!

bump - could you please say if something like that is possible? Thank you much!

@FlyingRaccoon sorry for bumping this yet again, but our planning would really
be assisted with your reply on this topic: a simple “use_legacy_fm = 1” entry
would match the equivalent “use_modern_fm = 1” and help us tremendously. Thank

Should I keep bumping this one, or is the lack of response a response in and
of itself? I would very much appreciate an official answer, so we know how to
plan ahead.

Hi there, Starting from SimUpdate 11, you will be able to use the option
“legacy_fm_only” in “flight_model.cfg” to achieve what you described. Best
regards, Eric / Asobo

That is great news, Eric - thanks!

@EPellissier is this now available in SU11 beta? Thanks,

Yes. This is listed in the release notes and documented flight_model.cfg