Fuel flow on p3dv5
I had my first flight on p3dv5. My fuel calculation from simbrief where way off. For this 2 hours flight , i consumed about 1000 kgs . I should have consumed ~2200 kgs.
The fuel flow indicated on the engine display in cruise shows a normal 500/500 kgs/hrs. But a calculate the amount of fuel remain over time and the rate is about twice as less. Is anybody else seeing this
Comments
Although we are not providing support for this platform as of yet, just telling us fuel is off by 1000kgs is insufficient for anyone to offer support not knowing weather conditions during flight (which as you are aware can have an impact on fuel consumption - although 1000kgs less seems a bit excessive). I recently performed a flight from New Haven Tweed to Washington National and estimated a 2400 lb burn and only burned 2105 lbs due to a 45 kt quartering tailwind.
It could be a bug, but we have not seen anything out of the norm for fuel consumption nor have there been any other squawks from within the community that I have seen/heard.
I had avg 20kt headwind component during the flight. I figured 1100kgs is impossible. I’ll wait for official release. Thanks
Here a test. No Wind/ clear skyies. Screen shots at 10 min intervals. Speed/alt constant 236 kts/FL150
Reported FF 1005kgs/h.
Mesured FF on fuel remaining 514 kgs/h
Did another test with plane configured in LBS.
Same conditions, 0 Winds/Clear sky , 236Kts /FL150
Reported FF: 2213
Mesured FF on fuel remaining: 1092
Provide the route,....please and thanks
Take of CYUL 6L, going strait 63o
Hi,
In the example I provided in the screenshot above, I provide a the simplest scenario that I could. I ran over the course of only 20 minutes.
1)I lifted off from CYUL and flew to FL150 heading 63 degrees and stabilized at 236 knots clear day no winds
2) took a screenshot at t0:
- On the ED: FF reported was 500+500 = 1000kgs/h. FUEL: 2335+2330=4665
- On MCDU: FF = 1005kgs/h, FUEL ONBRD= 4586kgs
3) took a screenshot at t=20mins
- On the ED: FF still 1000kgs/h. FUEL = 4495kgs
- On MCDU: FF =1005 kgs/h, FUELONBRD =4420kgs
So
I am trying to understand the difference the discrepencies ~1000kgs/h vs ~500kgs/h
The whole issue was triggered when I ran a tour leg in on my VA (canadianexpress) and I the VA logger reported much lower fuel used then what the fuel calculate done by Simbrief.
While Simbrief is a great tool which I have used form time to time, will provide some inaccuracies unless you have a proper understanding for the proper loading of the aircraft which is not always straight forward unfortunately.
The Q400s loading template is driven off of the CPAN as you are aware and the parameters of the CPAN are specific for the most part not allowing for internal edits except for the DOM/DOI (which if changed must match). The defaults are 40639/94.6, which of course in Simbrief you must use when planning unless you have a lesser DOM with the associated DOI (hope I am not confusing you as yet).
Also if I recall, Simbrief when adding passengers also adds a baggage load of 55 lbs by default, I am not sure sure if you can set specific pax and bag loads for planning, but I am sure that you can customize an aircraft profile to match the actual parameters. So if you choose 72 passengers @175lbs each a bag count of 72 bags @ 55lbs each, would be added thus giving you a payload of 3960lbs for bags and 12600lbs for pax for a total of 16560lbs, and including you fuel uplift of 10263lbs.
These values unless corrected in Simbrief will still provide differences as the Q400 CPAN uses 186.9 per pax and 37.4 per bag, so the CPAN will actually load into the Q400 a pax load of 13456lbs and a bag load of 2692.8lbs for a total load of 16148.8lbs which would be about a 411lb difference. Which could be baffling if trying to figure out where the 400lbs difference is coming into play.
Not knowing how you compiled your flight one can only assume that you had a lightly loaded aircraft which could have caused the burn values to be off. As I also mentioned this could be a bug but it has not been brought to our attention as of yet. We'll keep an eye on it while performing some of of our other tests.
Cheers
Regardless of load out or what Simbrief and calculated, the actual fuel burned as reported by the software does not match the fuel flow used during the reported period of time. My question remains: why is there a 2x factor ( 1000 vs 500 ) different reported by the software own display for Fuel Flow and fuel remaining on both ED and MCDU. Or are my calculations wrong?
Not that it matters, but my ZFW was 24400kgs. initial FOB 4878kgs.
I guest I am trying to bring this to your attention
Fair enough, which as I mentioned we'll look into as we continue our testing.
So after doing some additional digging into your issue, I have a few questions.
Sorry for the late reply
1) yes, I have updated to windows10 2004. Nvidia 450.99, P3DV5 HF1
2) Timing source : Queue Timer
Let's give using the MULTIMEDIA TIMER a try and see if you are able to observe the required results.
I've set the time to "MULTIMEDIA TIMER" and did 2 tests KRND and CYUL and Fuel flow and fuel remaing delta calculations now match. So I will leave that setting on my system.
This is the first I was monitoring my fuel remaining so closly because of my VA activity. So I cannot say if I had this issue before.
Would you be able to confirme that this could be trigged by P3DV5, Windows10 2004, both , or is system dependent. I would like to report this back in my VA forum. I do admit that I am bleeding edge here, as P3DV5 is not officially supported, But Since I don't have my P3DV4.5Hf2 setup anymore and is already running W10 2004, as I cannot conclude myself.
Thanks for your help