Duct pressure problem 744...please help

[Guest KevinS13]

Hello,I think I may be having a problem with the duct pressure during startup on the 744 PAX version and I'm not sure if it's me or something else. I start cold and dark and go thru all the checklists, start the apu, apu bleed air on. At this point, with the packs off I am only getting 23 psi for the duct pressure. I have tried all combos of packs all on, all off, one on two off, etc. I have also tried the isolation switches on and off and I never get more that 23 psi on the duct pressure.Based on this psi value the autostart system does not work, although I can eventually get it started using a manual start.Anyone have and tips or suggestions to help out? Thanks,Kevin Shea

[Qavion 19]

I believe this question was answered yesterday, Kevin ;)Cheers.Q>

[Guest KevinS13]

Well, sort of....(if I'm thinking of the same thread) that guy could actually get started using autostart, and had 27 psi, mine is 23 psi and autostart failsAny other ideas?Kevin

[Guest kame]

Hi Kevin,I can autostart with either 27psi (one pack off) or 19psi (two packs off).Did you the engines breed air on?Sincerely,Kan-ichiro Fushihara

[Guest KevinS13]

Kan-ichiro,I have tried all combos of bleed air, etc and can't seem to get more than 23 psi at all. Thanks for the reply, I guess it's manual starting for me:-( Kevin

[Chaos81 110]

Kevin, by chance could you take a picture of the overhead when you are trying to do an autostart? That way we could see how you have everything set up, and it would help us figure out what you are doing wrong. :)If you do take a shot, make sure it's big enough so we can see it. ;)

[Guest kame]

Hum,I can start engines with either auto or manual.Sincerely,Kan-ichiro Fushihara

[Qavion 19]

Do you also have Nacelle Anti-Ice selected? Or perhaps are using Ext air? (which might not have a variable output to compensate for increased load).Cheers.Q>

[Guest KevinS13]

Thanks for the replies, I will try to get a picture of my setup, however I just follow all the checklist items from the cold and dark setup at Everett field using the PMDG select a flight option. I know for sure I'm not using nacelle anti ice and I don't think I am using Ext air, I'll have to check that one.Thanks again,Kevin

[Guest KevinS13]

Here are shots of the overhead config I have and a shot of the panel showing the duct pressure at 23psi. I can't even get the duct pressure to change at all when I turn all the packs on, one on and two off, two on and one off, etc. If I turn off one isolation switch the pressure on that side drops to zero, but I can never get anything above 23 psi period. BTW, autostart will not function in this setup I have, when I pull the start knob the white light does not illuminate.Here are the shots. Hopefully you can see the overhead shot well enough, I had to edit it a bit to get it under the size limit.Thanks,Kevinhttp://forums.avsim.net/user_files/146059.jpghttp://forums.avsim.net/user_files/146061.jpg

[Guest SKireyev]

What happens when you turn the fuel pumps on? What I see different from what I do, is that also, the 4th Hyd Demand Pump should be in auxilary position (AUX). Packs don't matter as I recall, since Autostart configures them for start-up.

[falcon999 24]

As Sergey mentioned you need fuel to start the engines. :-)Turn the pumps on and they should fire.

[Guest s_L_Y_F_a]

well folks,I tried to start up engines with exactly same config as shown on screens and it worked wellp.s. even with all fuel pumps off, engines will start and before you ask, no its not a bug, its boeing!

[Guest KevinS13]

So what was your psi value on the duct pressure? In my screen shots I didn't have the fuel pumps on because I was just showing the duct pressure problem I am having which is only 23 psi. When trying an autostart I obviouly turn on the fuel pumps. I am just trying to figure out why my duct pressure just sits at 23 psi regardless of what I do to anything in the air system.Kevin

[Chaos81 110]

Doing some more testing.