747-400 range performance

[jlstrum]

According to online sources, a 747-400 should burn about 20,000 lbs of fuel/hour at maximum range cruise of Mach 0.80 at 35,000 feet.  Using those parameters in FS2002, I get less than 8000 lbs/hour.  I was able to complete an unrefueled around-the-world flight (49 hours!), which the real bird would certainly never do.  is there a patch for this anomaly?

[IanK]

FAQ 42:

Does anyone know if, in FS2002, there is a way to adjust the fuel burn in jet aircraft?



Hello,
yes we do. Other than adjusting the throttle, do you mean the specific fuel consumption (SFC). The default is 0.5 h-1 which is multiplied by the fuel_flow_scalar in the .cfg file. Concorde is a bit different with reheat etc.

Ian

[Poseidon]

Has anyone else experienced such low fuel consumption? Just yesterday I had a flight from LGAV (Athens) to HECA (Cairo) which is about 630 miles and burned 50000 pounds in about 1.5-2 hours (I have not the flight form with the exact figures before me now) which makes a consumption of 25000-33000 per hour. I was flying at FL400 with 0.9 mach but such difference seems not reasonable.

[IanK]

Hello Poseidon,
Have a look at the FMs though only for -200 with JT9D-7R4G2 engines.
http://perso.wanadoo.fr/hsors/FS_Soft/acftdata.html

For 630nm sector the plan for a landing weight of 470,000lb is:
1h 38min block time fuel load 36,000 lb. If all was burnt and no reserves that is 22,000 lb/h or 5,500 lb/h/engine. If cruise drag was (only a guess) say 10,000 lb that is a SFC of 0.55 h-1

This is for the recommended M0.85 cruise at FL410 as M0.9 may not be the most economic.

The fuel burn is very dependant on the aircrafts weight but you did not specify any. It can vary over a 2 to 1 ratio.

The MSFS fuel burn will vary between flight models from different people so you may need to be more specific when trying to compare different things.

Ian

[Poseidon]

IanK, I was misunderstood. I do not find strange the consumption I had, it is normal. I just wanted to spot the difference between this and jlstrum who experienced an unusually low fuel concumption. Of course 0.9 mach is not the most economic choice but I wanted to be there quickly.

The link you provide is an excellent one by the way !!!!