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ahinterl

MD-11 (F2004): smoke elec/air switch

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I don't fully understand the purpose of this switch on the elec panel: abnormal procedures say it's used if smoke is detected, the switch is turned from one position to another, and flight crew looks whether smoke situation improves or not. So far I can follow, but why is a certain elec. bus shut off together with a pack with another number (the labels on the switch are like "1/3" or so) where I assume the switched off elec bus doesn't power that pack?Furthermore, is smoke simulated so this switch would be of some meaning in the sim?Andreas

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I saw an answer to this recently... the switch toggles electrical somehow as an aid to quickly isolate a problem but is not intended to be the solution to an electrical problem. Its function is described in the system manual starting on page ELEC.30.1 (Andreas, did you look there first?)A smoke canister at just above your keyboard might be able to simulate smoke in the cockpit.I flew an AF C-141 simulator in the early 70's that in fact had smoke canisters that would fill the cockpit with smoke. I was unprepared for that surprise.

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I saw an answer to this recently... the switch toggles electrical somehow as an aid to quickly isolate a problem but is not intended to be the solution to an electrical problem. Its function is described in the system manual starting on page ELEC.30.1 (Andreas, did you look there first?)
Firstly: Thank you for the informations. And yes, I first look in the manuals and try to find an answer myself. My problem is, and I have expressed this already in another post, that I don't find the manuals "overly informative" so to say. Agreed, they contain tons of informations, but they lack valuable information as well, or they're not verbose enough for my taste.Take the smoke elec/air switch as a good example: The function of this switch is explained in detail, but on the other hand, I for myself miss the information in what relationship one pack and another power circuit have, i.e. for what reason the combinations for elec and air at the various switch positions are how they are.Andreas

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Andreas: The text in the manuals is mostly direct from the MD11 manuals. I believe the information you are looking for (dependencies and what is on what circuit) is found elsewhere. For smoke, the procedures begin in the QRH page 20.9 but as far as which bus powers what box I am not clear. I think studying the FCOM is as close to understanding the dependencies as we can find.

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I think studying the FCOM is as close to understanding the dependencies as we can find.
Don't think so. When PMDG modelled the systems, they needed to have an extensive list of systems dependencies for all available systems. That alone would fill dozens of pages I guess. And this is not in the FCOM that comes with the MD-11...Same problem for fuel: PMDG needed to have a thorough description of every phase of the automatic fuel schedule to be able to program the fuel system. If you're solely in manual mode, you have little reference on how to distribute and transfer fuel during the flight by hand I guess. Maybe the FCOM in this case contains everything needed, but even if so, you need to collect the information piecewise from various locations in the manual and spend much time trying to understand the relationships. Why didn't PMDG print the schedule algorithm as an intuitive flowchart or so?Andreas

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Don't think so. When PMDG modelled the systems, they needed to have an extensive list of systems dependencies for all available systems. That alone would fill dozens of pages I guess. And this is not in the FCOM that comes with the MD-11...
This discription (refered to as "circuits inoperative") is indeed missing in the manuals. I know such table exsist in RW, needing only two pages however.
Same problem for fuel: PMDG needed to have a thorough description of every phase of the automatic fuel schedule to be able to program the fuel system. If you're solely in manual mode, you have little reference on how to distribute and transfer fuel during the flight by hand I guess. Maybe the FCOM in this case contains everything needed, but even if so, you need to collect the information piecewise from various locations in the manual and spend much time trying to understand the relationships. Why didn't PMDG print the schedule algorithm as an intuitive flowchart or so?
If you want to, or have to, operate the fuel system in manual, have a look at the Normal Procedures Checklist.Its all in there, but you should have at least a very basic knowledge of the fuel distribution / usage from the system manual.Regards,Harry

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