Aircraft Editor destroys Helo-Turbine engine configuration

Version: (existing since SU11)
Frequency: Consistently
Severity: Blocker (but the workaround is to not use Aircraft Editor to manage the cfg files)
Context: Turbine helicopters

Bug description:
Aircraft Editor destroys turbine helicopter engine configuration. The aircraft engines don’t work after saving, and the diff shows critical parameters are removed.

Repro steps:

  1. Get the Cabri G2 SDK sample
  2. Get the FLT and CFG files from \microsoft-aircraft-bell407\SimObjects\Airplanes\microsoft-aircraft-bell407. Do not take aircraft.cfg. Replace the Cabri SDK sample files with these.
  3. Load the project in MSFS
  4. Observe stable rotor rpm and the aircraft is flyable. (Use Debug → Aircraft → Engines to see the data since you are in the incorrect Cabri cockpit without correct instruments
  5. Now open Aircraft Editor and on the Engines tab, change the engine position. (Any change should be sufficient as long as AE can do its save process)
  6. Reload the aircraft and observe NR decays to zero
  7. Using version control, view the diffs from engines.cfg BEFORE and AFTER
  8. Observe that AE has removed critical engine parameters, RPM_on_TP_torque_table and n1_to_shaft_torque_table are critical. There are many more edits.

Essentially AE seems to not handle the Helo-Turbine engine type.

Hello @davux3

It is likely related to this bug report: [SU15] AE removes TURBOPROP_ENGINE section - Flighting SU15 - Bug Reports / Aircraft - MSFS DevSupport (

But I’ll double check the parameters you mentioned specifically.


Yes, it looks the same.

It’s worth checking specifically with the 407 after whatever fix goes in, because I did have the same behavior after SU11 when testing out flight model stuff. So, something could be hiding there beyond the bug - but it does look identical.

Do we agree that it’s not just the n1_to_shaft_torque_table that is removed but the whole TURBOPROP_ENGINE section?

From the TURBINEENGINEDATA section, the ones that seem to be missing are:


Yes that’s correct. For TURBINEENGINEDATA these are also missing…probably the fuel pressure related ones will be needed.

;[REMOVED]fuel_press_max = 240
;[REMOVED]fuel_press_tc = 2
;[REMOVED]fuel_press_tuning_constant = 1

The fuel ones are legacy fuel parameters, it will only be available if you to check the “Use Legacy Fuel” in the fuel section of the flight model tab (or remove the FUEL_SYSTEM section from the file).

And all N2 related parameters are only applicable to jet engines.


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So if it is removing the sections not needed, let’s say I’m running a modern fuel system and the n2 is not needed for turbine engines on my helicopter, then we need to figure out what the cause is that my engine won’t spin-up without the other parameters.

Or is this still a logged bug within the other parameters being removed (including the entire section) that is breaking the engine?

If the only difference between a version of your package that behaves as expected and one that doesn’t is that it has been edited in the Aircraft Editor prior to building the package, this is likely related to the bugs that have been reported on helicopter turbines.

If you provide us with your package sources, we can test it to make sure our fix candidate solves the problem.


Hello everyone,

The current SU15 flighting build ( has a fix to address this.
Come back to us if you still have issues.


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