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boufogre avatar image
boufogre asked Yoanito answered

New bleed air SimVars

Hello,

In the SDK v0.20.1 release notes, we can see the following:

1666855049130.png

However, the SimVars are absent from the documentation.

What are their effects and how to use them?

On a similar topic, the following SimVar is listed in the documentation, and I can see its value changing but what is the logic behind the value it takes?

1666855537197.pngIs it related to bleed air fed to the engine for start, or bleed air control from the indexed engine?

Thank you.

aircraftflightmodel
1666855049130.png (35.5 KiB)
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Yoanito avatar image
Yoanito answered

Hello @boufogre

The pages describing the effects of those variables wasn't ready when the flighting (beta) version of the documentation was released, it will be explained in the official documentation when SU11 will go out but here's the state of the page from our side.

For the BLEED AIR SOURCE CONTROL simVar, the value change the source of the bleed air used by the plane, if you want to set up the bleed air fed to the engine for start you need to use APU_BLEED_PRESSURE_RECEIVED_BY_ENGINE


Best regards,
Yohan


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boufogre avatar image
boufogre answered

@Yoanito,

Thank you for the explanations.

I am still having doubts on how the BLEED AIR SOURCE CONTROL SimVar value changes.

For example, on the default 747, when all the engine bleed air switches are ON, and the APU bleed air switch is ON too, it will return 0, which is min according to the doc (not sure what min means though).

1666860149612.png

But if switch the APU bleed air switch to OFF, then the BLEED AIR SOURCE CONTROL SimVar returns 3, which is APU according to the doc. That does not make sense, or am I missing something?

1666860340081.png

I have to say I understand the idea with the TURB ENG N1 LOSS SimVar, but IRL if you increase bleed air demand, ie switch on EAI or WAI, the N1 for a given throttle position will increase, while the maximum rated N1 will decrease to respect engine limits.

After testing the TURB ENG N1 LOSS SimVar, it appears it will only reduce N1 for a given throttle position.



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boufogre avatar image
boufogre answered

I think I found something.

It would seem the SimVar doc is outdated, and the correct information is given in the Event IDs section.
1666863554381.png

Could you confirm?

Thank you.


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Yoanito avatar image
Yoanito answered

Hello @boufogre

After a quick look in the code we realise that the documentation was false, 0 stand for AUTO so it will be returned when you have the engine and APU active, if you disable the APU you will go to Engine so 3, the documentation will be updated at the release of SU11 to display the following :

Best Regards,

Yohan

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