Lear 35A fuel burn question

[bpcw001 22]

Dave,

 

Great, keep us posted, would also like to get the fuel flow a little more accurate and it looks like you might be there :wink:

 

Cheers

Martin

 

Well, you can just go ahead and try the fuel_flow_scalar = 1.49 in the aircraft.cfg as well. Make a backup of the original aircraft.cfg file first.

 

I currently have only two pillars which I can base the tweak on: the Gary's "rule-of-thumb" and the data he posted here.

Also, I am not sure if a simple fuel flow adjustment will do for any case; the aircraft might still exhibit a totally different fuel consumption behavior in different conditions because of the flight model.

Tinkering with engine or other aircraft parameters is beyond my knowledge.

 

Still, I think it is better than the default. I'll settle with it for now. Let's wait and see if Flysimware comes up with something in their next updates.

[JackJones 3]

I recently did a "long range" flight from HEMA to EDDK and planned this with PFPX (with my LRC data - see seperate thread)

I had the following values:

ZFW:  9895
TOW: 15974
FUEL: FULL

TRIP...........5029 lbs_________05:31 h
CONT...........251 lbs_________00:20 h
ALTN............159 lbs_________00:07 h
FIN RES.......380 lbs_________00:30 h
EXTRA.........260 lbs_________00:21 h
TAXI.............200 lbs_________00:10 h
RELEASE..6279 lbs_________06:59 h (this looks not really realistic to mee)
ARR FUEL...950 lbs_________01:12 h

ACTUAL ARRIVAL FUEL WAS: 300 lbs, after 05:31h actual flight time  [T/O @ z0755 and Landing @ z1326
My fuel conter showed: 5900 lbs used

250 kts until FL290
0.74 until FL400

FL400 for the first 3h then FL420.

I did quite a lot of fuel checks, I had time enough ;), and in average I could see a +100-150 lbs/h fuel consumtion (of course it´s higher at the beginning - first hour was 250 lbs/h, due to climb etc.)
I was flying the TAS out of the NAV LOG most of the time.

I know this is a bit of "nit picking", but at the end it makes 650 LBS less of fuel on your arrival airport with very less options left...just in case, you know...

As well I noticed something complete different: The entire flight there was no noticable pitch change! Pitch was always about 2° up and the trim FULL nose down!
This seems not to be correct, especially when flying with M.70 - M.66 at the end.

 

[JackJones 3]

I did another flight (atlanctic crossing EINN - CYQX) today, after I´ve read the comments in this toppic and due to thus, if "tweeked" some of my files as following:

-> short details: flight time= 05:18h, remaining fuel 650 lbs (planed trip was 04:58h with trip fuel:  4960 lbs) due to stronger headwinds it took a bit longer...

FSW Lear 35: 
aircraft.cfg            fuel_flow_scalar = 1.49 (as already written above)

This change get me better fuel consumption as before! It went down from average +150h to about +40 lbs/h.
Due to that i will adjust the fuel flow to 1.485 for my next flight and think this should solve my actual "additional" fuel consumption.

PFPX Lear 35 -> AircraftTypes -> Learjet 35A.txt:

I changed the below highlighted data, as the provided values didn´t match the ones from the FSW aircraft.cfg file.
The "empty weight" in the aircraft.cfg file is 10361 lbs. As per Standard FSX is adding two crew (PIC + SIC = 340 lbs total / 77KG per person).

- > As well I changed the weights for MTOW, MRW according to the books to the "published" values for the Lear35. 😉


[DEFAULT_DATA_KG]
DOW=4854
MZFW=6028
MTOW=8300
MRW=8391
MLW=6939
FuelCapacity=2848
TaxiFuelPerMinute=9
APUBurnPerHour=0

[DEFAULT_DATA_LB]
DOW=10701    
MZFW=13290
MTOW=18300
MRW=18500
MLW=15300
FuelCapacity=6279
TaxiFuelPerMinute=20
APUBurnPerHour=0

For PFPX users, a little note:

You may need to manually edit your aircrafts "Empty Weight" to 10.701 lbs, in the aircraft database, as this is the value for the DOW (including two crew) !!!