Helo-turbine: Bleed air not required to start it

Dear development team, I setup up the engines.cfg like this:

engine_type = 3 ; 0=Piston, 1=Jet, 2=None, 3=Helo-Turbine, 4=Rocket, 5=Turboprop
starter_type = 2 ; 0=Electric, 1=Manual, 2=Bleed Air

I close the bleed air through:
SimVar.SetSimVarValue(“K:BLEED_AIR_SOURCE_CONTROL_SET”, “Number”, 1); and I
verify it through SimVar.GetSimVarValue(“A:BLEED AIR SOURCE CONTROL”,
“Number”); (It was 0 then it changed to 1) As per doc
(BLEED_AIR_SOURCE_CONTROL_SET) it should be off now:

Sets the bleed air system source. The input parameter [0] can be one of the following:

0 - auto
1 - off
2 - apu
3 - engines

If I try to start the engine throught the template
ASOBO_ENGINE_Switch_Starter_Template it stats without any issue. Just to be
sure I didn’t do anything wrong on my side I changed in engine.cfg the
engine_type to 1 (Jet) and with the same test the engine does not start (but
it start if I set the bleed air to 0=auto) . It seems to me that the helo-
turbine just ignore the starter_type variable, or am I doing anything wrong /
missing? Thank you for your support

Dear Asobo,

After a few months I could get back on this topic.

I created a minimal example for you to test it.
I took the Cabri G2 sample and replaced the flight_model.cfg, systems.cfg and engines.cfg with the B747 ones.
I will attach the new files here. My tests was by sending K events directly through Coherent GT Debugger and monitoring A vars through SimVarWatcher.

The behaviour with Cabri G2 with B747 files has the correct start up behaviours. There are the steps I used to validate it:

  • Turned battery on through the Cabri battery cockpit switch
  • Sending JS command: SimVar.SetSimVarValue(“K:APU_STARTER”, “Number”, 1)
  • Waiting for APU RPM to reach 100%
  • Sending JS command: [ SimVar.SetSimVarValue(“K:SET_STARTER1_HELD”, “Number”, 1), SimVar.SetSimVarValue(“K:STARTER1_SET”, “Number”, 1) ]
  • Monitoring ENG1 N2 raising
  • Sending JS command: [ SimVar.SetSimVarValue(“K:SET_STARTER1_HELD”, “Number”, 0), SimVar.SetSimVarValue(“K:STARTER1_SET”, “Number”, 0) ]
  • Monitoring ENG1 N2 dropping
  • Sending JS Command: SimVar.SetSimVarValue(“K:BLEED_AIR_SOURCE_CONTROL_SET”, “Number”, 1)
  • Turning again the starter on: No any change in ENG1 N2 RPM
  • Sending JS Command: SimVar.SetSimVarValue(“K:BLEED_AIR_SOURCE_CONTROL_SET”, “Number”, 2)
  • Monitoring ENG1 N2 raising until the engine is started
  • Sending JS Command: SimVar.SetSimVarValue(“K:APU_OFF_SWITCH”, “Number”, 1)
  • Try to start engine number two (same command as above with index 2) : it works if I set the air source control set either to auto or to engine. When in off or in APU position the engine does not start even with starter on

Now, in engines.cfg I changed the line
engine_type = 1 ; 0=Piston, 1=Jet, 2=None, 3=Helo-Turbine, 4=Rocket, 5=Turboprop
engine_type = 3
and performed a very simple test: with apu off running turning on the starter (as in the above example) and the ENG1 N2 start immediately to raise.

Can you please confirm this bug on your side as well and is there any plan to fix it and in which SU?

Thank you very much for your support

PS: Here are the files I am currently using (engines.cfg, systems.cfg, flight_model.cfg) :
(I am sorry but it seems I cannot attach files nor adding links to a shared folder)
They are the same as the B747 with the following differences:

  • Changed the four engines position for a CG question
  • Added the [AUXILIARY POWER UNIT] Available = 1 lines

I also uploaded a SimVarWatcher variable list file (I paste here the original content)
ENG N1 RPM:1,percent,False
ENG N2 RPM:1,percent,False
ENG N1 RPM:2,percent,False
ENG N2 RPM:2,percent,False
APU PCT RPM:1,percent,False
APU PCT STARTER:1,percent over 100,False