Removing deprecated(!) variable "fuel_flow_gain" from engines.cfg causes system breakdown

Removing the variable fuel_flow_gain from [TURBINEENGINEDATA] causes several
weird behaviours, even though the documentation clearly states it being
deprecated and not used anymore.

Some observed behaviours (non exhaustive) when leaving out the variable

  • breaks all CIRCUIT_FUEL_VALVE, without possibility to turn them on again.
  • N1 and N2 fixed to 100%
  • cuts off valves to engine

Do not always trust the SDK as it could have mistakes or need to be updated. I
use a program called grepwin and you can search key works so right now Asobo
default planes that use this cfg setting are here in the image shared. Looks
like jets engines or turboprops need this cfg.

Hello @GutsherrBus9 We have identified a bug where missing parameters will
cause the turbine config reading to silently fail and leave some parameters
uninitialized. For now, the parameters I have identified as causing the
problem are: fuel_flow_gain static_thrust inlet_area
rated_N2_rpm afterburner_available inlet_area and rated_N2_rpm
are documented as required so I think everyone defines it and it’s not causing
much problem. But the others are either optional or deprecated, but still
cause this problem when missing. We have fixed the issue on our side but in
the meantime, you want to make sure those parameters are defined in your cfg
and you can edit the FileDefs_AircraftEditor.xml file in the fs-
package and remove any exclusion element to prevent the
AircraftEditor from removing them on save. For example, for static_thrust
, you want to remove this part:

Thank you for reporting the problem and our apologies for the setback.
Regards, Sylvain