PMDG 747 400 APU Start

[Check_Airman 3]

>You seem to be saying that ALL the pumps are powered by>Utility Busses. Switch off the Util Busses and you will see>that this is not the case. Note: Since the power supplies to>the PRESS light lamps is also modelled, you may not get all>the PRESS lamps lighting up (so you may have trouble>identifying which pumps are actually working by depowering>various busses)In this case, would the EICAS synoptic give an accurate picture of the actual pumps that are working?Paul

[Qavion 19]

"In this case, would the EICAS synoptic give an accurate picture of the actual pumps that are working?"Correct, except:1)the synoptic won't show you the #2 Aft boost pump operating when the APU is running2)the synoptic needs certain busses to be powered before it will display.Cheers.Q>

[Guest pilotbrian0]

Synoptic can be displayed on the Captains Secondary Display using the Battery. Out of curiosity, I went through and tested it... here's what I found:Bus 1: 3Fore, 2Aft boostBus 2: 2/3 Fore Override Pumps, 1 Aft, 4 Fore boostBus 3: 2 Fore, 3Aft boostBus 4: 2/3 Aft Override Pumps, 1Fore, 4 Aft boostI didn't have enough fuel onboard to test the Center or Stab pumps, but I'm guessing their tied to Bus 1 or 3 based on what I've seen so far.-Brian

[Qavion 19]

LOL... silly me...Brian... I was under the impression that you were a real 744pilot. I see from your post further up in the thread that you are not.I was scratching my head for a while there.... I thought you were seeing all this stuff in the real world.Cheers,Q> (Real world 744 Maintenance Engineer)

[Guest pilotbrian0]

I honestly wouldn't be basing anything I post here off the real world anyways, until such time as a comparison comes into play (as happened on another thread).I have several friends who are 744 pilots, I myself am currently a private pilot w/ instrument, but not much more.Either way, I think that the community here, while benefiting from a real world view on how the thing works, would benefit more from a Sim view, since that is what we're all flying here.It's great that you have experience with the real thing, and I really envy you, but yes, my observations are sim observations and are, in my opinion, much more pertinent to the operation of the sim, especially since the original question was about lights in the sim.I'll get gas in my sim plane and check the other pumps soon.-Brian

[Qavion 19]

"The FQIS is the brains of the refuelling system. The FQIS is normally powered by Main Busses 3 and 4, but I will look into the matter further."OK, the ops manual statement is starting to make sense to me now....When the Wing Fuelling Station panel is opened, this action actually forces the FQIS to use the Ground Handling Bus (or the Hot Battery bus, if the Ground Handling Bus is not available). An electrical reed switch is activated when you open the panel. With the panel open, the FQIS Processing Unit (inside the FQIS) is forced into a refuelling mode (you will see a Preselect value appear on the Fuel Synoptic in the cockpit... (not modelled in PMDG)).Of course, even with a totally dead ship, enterprising engineers could still refuel an aircraft using manual override of the refuelling valves. Fuel quantities in the tanks could be monitored using the built-in fuel measuring (dip)sticks (each tank has one or more sticks), but you won't have overfill protection... Load too much fuel and the fuel will start spilling out of the wings.Cheers.Q>