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Post by Mike Monce - HJG on Aug 4, 2019 12:23:05 GMT
I'm not normally a grammar obsessive, but your continuous run on sentence is very hard to follow. Could you restate what is happening?
From what I can discern, fuel is being used properly AS DESIGNED BY MSFS. However you want to follow a precise checklist from an airline??? Well, that sort of system realism is rarely available in MSFS. PMDG and the latest DC10 panel by our own George being exceptions. I think you are asking too much of a decent simulation and expecting a level of systems simulations that just doesn't exist with these DC9s.
Like I said, spend the money for a PMDG 747, try our DC10, or a Level D 767.
Mike
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Post by jardx on Aug 4, 2019 14:54:33 GMT
Sorry I type like I speak, I am not an grammar geek.
I respectively disagree I do not feel that I am asking for to much from this panel considering that for the most part everything else is simulated correctly and realistically. Take the Maddog08 panel by Leonardo, DC-9 80 series, it simulates the fuel system correctly like this panel does except that the logic is not messed up after performing the fuel crossfeed check realistically.
1. One BP on in a tank with usable fuel the fuel low pressure light in the respective tank goes out indicating that the pump is running and providing fuel pressure. (Note: All fuel tank BPs are AC powered except the start pump which is DC powered hence why you use the start pump to start the APU when you have no other source of AC power)
2. Open/turn on the crossfeed observe the other fuel low pressure light going out indicating that the fuel is going through the crossfeed and pressurizing the other side.
3. Close/turn off the crossfeed and observe the fuel low pressure light on the side that has no BPs on come back on indicating that there is no fuel pressure on that side.
When you config for engine start, 2 BPs on in all tanks with usable fuel in them and the crossfeed off/closed the logic should stay tank to engine if there is no fuel in the center tank and no BPs on in the tank or center first then wing to engine in the case of an aircraft with a three tank install.
All I have been saying is after doing this check realistically I noticed that this panels logic incorrectly will burn both engines from the right main tank until you cycle the BPs on then off. When I did the last engine run test after completing the check with 2 BPs on I saw the logic did not get messed up.
So this whole thread was I was wondering if anybody has seen this and if so was there an update for the panel that fixs this or not. I would say the answer is no there is not.
Finally, yes I have all of those simulations you mentioned. I feel to that freeware can be just as good if the developer of the panel/aircraft puts enough work into it which some do and some do not.
Jared
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Post by Mike Monce - HJG on Aug 4, 2019 19:23:34 GMT
Ok, that helps explain exactly what you are doing so that I can replicate the procedure.
I do think there may be a problem here. I didn't get your result, but something similar. DC9-30, I fueled with 10% center, 70% wings.
Started APU, and then noted the low pressure warning light for the right tank was not illuminated. I tried your test by turning on the right tank pumps, then engaging the xfeed, and the left tank light went out as per your criteria. Turned off the xfeed and the right tank low pressure re-illuminated. I couldn't repeat for the other side as I said the low pressure light for the right side was not on at all. I then started the engines leaving the center tank pumps off as it only had 10%. After starting fuel was drawn from ALL the tanks, including the center one even though the xfeed was off and its pumps were off.
There are many panel versions for the 30 model. Which one specifically are you using and does it match the engine? All those panels have minor differences, but I suspect the fuel logic will be similar or the same. I'd like to retest using the exact same panel/plane that you are using starting with the 30
Either way, this is nothing I can deal with. It will have to be looked at by George (I know zip about panel building and xml coding), if he has the time.
Mike
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Post by jardx on Aug 4, 2019 20:25:25 GMT
Mike,
Yes, sounds like you had the right idea for testing the crossfeed system with the right tank supplying fuel to the left side. The test should be the same if you want to check the crossfeed the other way except this time you turn on the left BP instead of the right, the opposite should occur if it is successful.
I checked the model/panel in terms of matching the right model/engine to the right panel with the matching engine for the reasons you guys at HJG state and they all match as far as I know but I will recheck.
I am not on my PC with FS installed as of this post so when I get back on the PC I will add another post with the specific model and version of engines I have installed but in short I have the -20, -30, -30F, and -50 airplanes installed.
I agree the basic fuel logic should be the same for aircraft with the three tank installation I can not speak for the ones with the two AUX tank installation as the example company I have the produces for did not operate, to my knowledge, -50s with two AUX tanks I believe they only had one AUX tank installed on their -50s.
Sounds like what you saw was the model operating like the engines could be gravity fed from the center tank which to my basic knowledge of fuel systems on jets is not possible if the engines are tail mounted like the DC-9 the only planes that I am aware of that can gravity feed is wing mounted models and even then it can only gravity feed from the associated wing tank.
I am with you on the knowledge of panel building and gauge coding I know nothing.
Jared
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Post by jardx on Aug 4, 2019 21:47:51 GMT
Here are the models and engine versions I have installed...
1. DC-9 20 JT8D-9 V1.13 2. DC-9 30 JT8D-15 V1.13 3. DC-9 30F JT8D-11 V1.13 4. DC-9 50 JT8D-17 V1.13
I rechecked the panel cfg files to see if they were aliased to the correct panel for the engines listed above and they are.
Jared
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Post by aerofoto - HJG Admin on Aug 5, 2019 0:38:56 GMT
What needs to be born in mind here is .... these panels were first produced during approximately 2005/6 (by Steffan HILMERBY an SAS DC-9 captain who's intention was to produce these as a "very basic" home PC familiaration/procedures tool for their pilots .... and with the FS community benefiting as spin-off from this). We were authorized to modify these panels from around 2008/9 .... and which included adding a number of features not represented within the original non-HJG releases.
Whether or not we further modify these panels .... for any reason .... remains to be seen and I give no guarantee that they will be.
Another detail that needs to be born in mind too is .... it's fine for people to suggest this, or that, isn't right .... but .... at the end of the day we can only compile on the basis of (a) our own skills/abilities .... (b) our own knowledge of how things work aided by the R/W AOM reference data we haver available to us .... and (c) sometimes we're limited in what we can, and would like to be able to, do by what's been previously done/compiled.
Point "B" is most significant because we have more AOM data for some aircraft types than others .... so .... what we end up offering isn't necessarily all of the same or a single set standard .... and at the end of the day, and for the aforementioned reasons, we can only do, and offer, what we can do and offer.
Mark C AKL/NZ
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Post by Mike Monce - HJG on Aug 5, 2019 17:47:38 GMT
So I did a fresh install of a DC9-32, using the JT8D-15 engine and panel and repeated my test. I got exactly the same results. The right tank low pressure warning light never illuminates, and then after doing the xfeed test before engine start, I get fuel drain from all tanks at once even with the center tank pumps off once engines are started.
I would say you've uncovered a small bug in these panels. I would just skip that xfeed test in your procedure then the tanks are used as they should be. As Mark stated, these panels date from a long time ago, so don't expect perfect systems simulation with them. If used without that particular test, then they work fine for flight. If George wants to take a look at them then that's up to him.
Mike
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Post by jardx on Aug 7, 2019 21:38:24 GMT
Alright Mike thanks for double checking that for me to be I wasn’t crazy.
Jared
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