CRZ Performance and fuel Forecast
Posted: Mon Jan 13, 2020 5:44 pm
I did a longer flight over 650 nm 2FL310. This is what I had on the MFD:
GS 362 and TAS 314 nice tail wind.
Acc. Loadsheet I had ZFW 11100 lbs and had loaded 2000 lbs of fuel for the 650 nm flight
Doing a check at that position showing only 18 lb as arrival airport I did a check.
Remaining flight time 470 nm/262 kts = 1.3 hrs = 1h:20min. Time calculation is correct!
Fuel on board 1340 lbs. 1.3 hrs x 740 lb/hr = 960 fuel to Dest, remaining 380 lb - a bit borderline but still okay.
So the fuel at destination calculation is not matching, though I entered it in the PERF INI correctly at DEP.
The other thing that puzzled me is the following (edited with tank volume changes versus what AFSD showed):
While the MFD says a FF of 2x 370 lbs/hr, the actual measured FF over 10 min flight and extrapolated is only 780 total lbs/hr. That is 5% off between actual consumption and FF showing on MFD.
The internal AFSD measurements seem to be irrelevant as the FF and real consumption is tuned individually.
Comments?
- Screen_19.jpg (57.45 KiB) Viewed 917 times
Acc. Loadsheet I had ZFW 11100 lbs and had loaded 2000 lbs of fuel for the 650 nm flight
Doing a check at that position showing only 18 lb as arrival airport I did a check.
Remaining flight time 470 nm/262 kts = 1.3 hrs = 1h:20min. Time calculation is correct!
Fuel on board 1340 lbs. 1.3 hrs x 740 lb/hr = 960 fuel to Dest, remaining 380 lb - a bit borderline but still okay.
So the fuel at destination calculation is not matching, though I entered it in the PERF INI correctly at DEP.
The other thing that puzzled me is the following (edited with tank volume changes versus what AFSD showed):
While the MFD says a FF of 2x 370 lbs/hr, the actual measured FF over 10 min flight and extrapolated is only 780 total lbs/hr. That is 5% off between actual consumption and FF showing on MFD.
The internal AFSD measurements seem to be irrelevant as the FF and real consumption is tuned individually.
Comments?