For the past few weeks I have been testing the engine model behavior for the A320 Neo and came up with some serious issues. FYI, these issues are also related to other Airliners.
It seems something is either wrong or not documented regarding the engines.cfg file. As you probably already know, there are a number of variables (mach_0_corrected_commanded_ne_table, mach_hi_corrected_commanded_ne_table, corrected_n2_from_ff_table, n1_and_mach_on_thrust_table, n2_to_n1_table and corrected_airflow_table) that are related to legacy FSX/ P3D .air tables. These tables relate engine parameters to give thrust characteristics at different altitudes, temperatures and speed. Well, from my experience, almost none of them are being used by the airliners when using the Modern flight model (haven’t tested Legacy).
The only table that seems to work is n1_and_mach_on_thrust_table, which all by itself it doesn’t have all data needed to calculate thrust at different conditions. I thought that maybe the other tables were somewhat hardcoded, but through testing you can experience that pressure and temperature do not affect N1, N2 and FF parameters.
Not sure if we should consider this a bug, a missing feature or just lack of detailed documentation, but as it is, it will be impossible to have a near realistic engine model.
I have opened a bug report at Zendesk …