Bleed Air Questions

[Mandretti]

I am following tutorials and videos and have run into an issue with bleed air.  The APU LCV and ISOL valves won't open.  I see in a post from last year that these won't open if the Engine Bleed is on.  In looking at the Study Doc for the 14th Stage Bleed System I see that the Right and Left Bleed SOV are both open.  I'm assuming those are the Engine Bleeds?   If so, the L and R switches are up/off. And pushing them does not actuate the valves either way according to the real-time diagram.  The PACK switches will go on, but I assume they are not actually doing anything without bleed air from the APU or Engines?  

And possibly related to that the DUCT MON switch will not move in any direction.  Thanks in advance for your help.  

 

Edited January 12, 2023 by Mandretti

[rjb4000]

Both the 10th stage and 14th stage bleeds are engine bleed valves. I can’t really tell from your screenshot, but you should make sure the 10th stage bleed valve switches are out. 
 

For the duct monitor switch, click and hold on the words (test, loop a, loop b) to rotate the knob to that position. 

[Graeme_77]

OK, so this is a complex one to explain. 10th stage is air conditioning and engine starting, 14th stage is anti ice.  10th stage is what we're interested in here.

The valves are pneumatically driven, that is to say they run on bleed air pressure. No bleed, the valves close. The 10th stage system is designed to prefer engine bleed over APU bleed.

What I think you've done is select L and R buttons to the IN position, but there's no bleed air so the valves remain closed. But then you've tried switching APU LCV and ISOL on by pressing in, and it doesn't work because the system is trying to command engine bleed rather than APU bleed. This is because you've got 10th stage L and R pressed in with no actual bleed air pressure. Switch those out and the APU LCV and ISOL will open.

See item 30 on the cockpit preparation Expanded Procedures, or use the hint images in the sim.

Edited January 12, 2023 by Graeme_77

[Graeme_77]

Here's the issue in two screenshots. First one has L and R pressed in, but still show closed as no bleed pressure. The APU LCV is closed despite being pressed in, because it prioritises engine bleed. 

Second pic shows the L and R pressed out. This allows the APU LCV to open, providing pressure to open the ISOL valve and everything is good for starting.

Incidentally watch the closed lights on L and R disappear as you press the start switch and they open automatically to allow starting.

[Mandretti]

Yes!!  Thanks so much.  BTW this AC is unbelievable as many others have noted.  Q8Pilot is over the top with this one.  Congratulations on producing the most advanced AC ever in the consumer sim arena.  And you folks are so responsive with questions and issues on this forum.  Amazing.  

I don't know when you started work on this project, but as a software engineer myself I know this had to be either a lot of work over a long period of time with a small team, or a huge amount of work in a short time period with a large team!   Either way - you did it!  I look forward to future products from you folks.