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Post by redindian421 on Dec 19, 2020 18:15:38 GMT
Hello,
I am enjoying your free DC-10 addon in FS9.2 very much. Thanks for creating this!
I noticed however, the fuel consumption/fuel flow seem way too low.
I took off FRA with the NWA DC-10-40 bound for KPDX, expected flught time 10 hours 13 Minutes. Block fuel was calculated on Simbrief using the DC-10-30 giving 100.4 tonnes or 100439 kilograms. More than 3 hours into the actual flight, total current fuel mass was shown as around94 tonnes on the FE panel, whereas simbrief gave about 68 tonnes of EFOB.
Can someone help here?
Thank you very much!
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Post by aerofoto - HJG Admin on Dec 19, 2020 18:43:35 GMT
What needs to be appreciated here is .... our F/F values are generally accurate "at SL" .... and when I say "accurate" I mean as close as we can achieve "IN FS" and based upon the official TSFC rates data we access for each engine type/aircraft type in order to determine basic F/F in relation to power and to start with.
Whatever happens to F/F on the way up to, and at, cruising altitude we ultimately need to "accept" .... and which can result in indications either higher or lower than reality since absolute R/W fidelity simply can't be achieved in FS by virtue of the fact the host program simply isn't supported by all of the necessary parameters.
Ultimate FF indications are going to be determined somewhat by simulated weight and cruising altitude .... and needless to say power setting/airspeed/MACH velocity too.
During pre-release testing I recorded the following F/F indications at FL310 and after a MGW departure and at economic cruise .... which we're quite comfortable with ....
Mark C
AKL/NZ
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Post by aerofoto - HJG Admin on Dec 19, 2020 18:52:02 GMT
Something else I need to say also ....
Based on what we've seen/had reported back to us over the years .... some flight planning programs can be less than accurate .... in either + or - senses.
Not suggesting this's indeed the case with SIMBRIEF .... but .... are inclined to suggest it's a possibility.
Mark C
AKL/NZ
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Post by redindian421 on Dec 19, 2020 19:01:33 GMT
Thank you very much Mark for your feedback! Much appreciated! I understand everything, even that simbrief's fuel burn calc for the 10 might be off, however, only 6 tonnes of total fuel burned off after about 3.5 hours into the flight (takeoff nearly MTOW, FL300 and Mach .82) seems very little. Hm. Please understand, I do not put down your hard work. I love it but I was wondering about this! Would it be possible to edit the air.file (using e.g. AirEd) to increase the SL FF rates? Of course I will keep the original file and would experiment for my own setup. Do you know which section in the air file would be the one to tackle? Again thank you for your quick response. Great support!  |
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Post by aerofoto - HJG Admin on Dec 19, 2020 19:25:25 GMT
That indication doesn't seem right to me either .... especially when "all 3 engines combined" are indicating a total fuel burn of some 18,222 LBS per hour (an imperial/non-metric based measurement/observation) following a MGW departure and FL310 cruise .... according to my own pre-release recordings I wouldn't be the least bit inclined toward, and nor would I ever recommend, doing that. The reason for that is .... beyond the TSFC value we apply in order to set the SL F/F rate as accurately as we can for starters (these will always be + or - and which, in FS, is something that simply has to be tolerated) .... F/F should always be dictated by "drag related parameters only" and never per further adjustment to the stated CFG based FFS value. I'd like to check this our myself, but, time's not on my side (unfortunately) to be able fly much between now and the New Year .... my wife and daughter/s say I've exceeded my flying time for the month  How do your panel indications compare with the FUEL LOAD (remaining) indications within the FS FUEL & PAYLOADS schematic and after 2 or 3 hours of flight ? JUST A THOUGHT ..... I assume your FS, and flight planning calculations, are based on LBS .... and not KG's !!!! Mark C AKL/NZ |
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Post by redindian421 on Dec 19, 2020 19:35:32 GMT
Thank you Mark!
I think I made sure, simbrief and fs shows fuel in kilogram.
I will check the panel indications against flight planning calculations and will report back here soon.
Again, thank you!
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Post by aerofoto - HJG Admin on Dec 19, 2020 19:46:48 GMT
That could be the foundation of your problem .... since the DC-10, and our calculations, are all based on LBS .... and not KG's.
Mark C
AKL/NZ
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