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G7USL

Starting the Q.O.S?

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I notice that, I can't start my engines until the fuel switch is on?Is this a bug? I noticed on the various 744 videos of reality flights that this shouldn't be the case. Fuel is fed into the engines when 'N1' reach '10' on start up or, so I thought?Please advise?


Dave Taylor gb.png

 

 

 

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I've found this too.. I have to switch the fuel to run before the engines will start to spin.. Would be interested if this is us or a sim limitation.. or if indeed it even is a limitation.. :)CheersCraig


Craig Read, EGLL

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Guest Ryan Briggs

actually, i believe it's neither.Correct me if I'm wrong (not 100% on this).Without Autostart turned on You have to have both the fuel switch and the starter in their position before the engines will do anything. Autostart off they run as conventional engines and fuel goes in when the pilot tells it to.

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I think that with the older generation engines you had to wait until about 19% N1 to introduce fuel. Now with FADEC you can select autostart and move the switch from cutoff. That was the start procedure on the ITVV Virgin Atlantic video as well. If you do not use autostart, then you introduce fuel the old fashioned way.Remember the preface, "I think.....". One of our RW operators would be better able to clarify.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png


Best-

Carl Avari-Cooper

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"I think that with the older generation engines you had to wait until about 19% N1 to introduce fuel. Now with FADEC you can select autostart and move the switch from cutoff."FADEC and Autostart are kinda different things. You can have a FADEC engine, but the airline may not have chosen to include an Autostart switch(es).But, yes, during AUTOSTART, you have to pull the start switch and lift the fuel lever to get the EEC to begin the start process (the EEC controls the start valve and fuel&ignition). Switch off the AUTOSTART and you will have to put the fuel lever to run at the appropriate time (some drivers probably put the fuel on as soon as the N2's rise above the magenta marker.... others like to get the N2's as fast as they possibly can ("max motoring")).So... PMDG is modelled PERFECTLY. NO BUG HERE.Note also the illumination of the light in the start switches varies depending on whether you have Autostart selected or not.Cheers.Q> (Edited for spelling)

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Guest Ryan Briggs

that light means the engine is recieving Bleed air to begin motoring right?

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"that light means the engine is recieving Bleed air to begin motoring right?"Basically, yes. The light is an indication that the valve which supplies air to the pneumatically-driven starter motor is open. The valve needs a certain amount of air to open it, so the light usually indicates that there is (some) bleed air available for start (although not necessarily enough air to get the N2 rotor spinning fast enough for a proper start)). There are electrical microswitches on the start valve to indicate its open/closed state (and the microswitch circuits illuminate the light).At just over 50% N2, it's important that this light goes out. If it didn't, the starter motor might still be engaged with the engine N2 rotor. If it doesn't disengage, the starter is very likely to self-destruct in a short period of time.Hope this helps.Cheers.Q>

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