JAM747
Topic Author
Posts: 524
Joined: Thu Feb 03, 2005 12:17 am

FS2004 Calculations Vrs Real World

Tue Oct 18, 2005 5:54 am

When I do my flight planner for a flight on FS2004 it gives certain calculations such as distance in nautical miles between points, direct route, estimated fuel needed for the journey, estimated fuel burn, estimated time etc depending on the aircraft. I know it is a computer and in the real world different factors could create different figures. Are there any real pilots on here that also use FS2004 and have actually made comparisons between the two. I often fly long and odd routes on my FS2004 with A 747-400 (not sure if it is the ER). For example I am currently flying from Sao Paulo Brazil (GRU) to Tokyo Nartia (NRT) via Georgetown Guyana. This stop in Guyana is in path of a direct route from GRU to NRT. I left Guyana with max fuel and I am experimenting to see if I get to Narita non-stop without making a fuel stop. I don't think I will make it, but so far my fuel burn ( in terms of gallons per mile) is less than the original flight plan had indicated. I am trying to estimate if Guyana or Barbadoes ( which is also on the route) could in real life be a stop for an airline going from NRT to GRU. Recent trends in the civil form have been discussing possible stops which avoid U.S, Mexico and Canada between these airports . That is why I am curious and doing this experiment, but wonder if it will give me a feasible answer. Thanks.
 
A3204eva
Posts: 1041
Joined: Wed Feb 18, 2004 4:25 am

RE: FS2004 Calculations Vrs Real World

Tue Oct 18, 2005 8:58 am

Although i've never compared them, the r/w routing can be different, as ATC may route them differently for whatever reason
"They have lady pilots......... they're not that good, but they have 'em"
 
mandala499
Posts: 6458
Joined: Wed Aug 29, 2001 8:47 pm

RE: FS2004 Calculations Vrs Real World

Tue Oct 18, 2005 12:38 pm

In addition to the above...

A plan is a plan... the FS2004 plan and the real world plan would be very similar if not identical for routes using the same airways... the differences would be yours vs. company policy...

The fuel burn calculations are the inaccurate thing in FS2004 default flight plan. Some addons can do this very well... For me, whenever possible, plan the fuel manually  Smile Benchmarks often work better than the automated process... even in real life!

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
JAM747
Topic Author
Posts: 524
Joined: Thu Feb 03, 2005 12:17 am

RE: FS2004 Calculations Vrs Real World

Tue Oct 18, 2005 1:35 pm

Quoting Mandala499 (Reply 2):
The fuel burn calculations are the inaccurate thing in FS2004 default flight plan. Some addons can do this very well... For me, whenever possible, plan the fuel manually Benchmarks often work better than the automated process... even in real life!

Mandala499

I think you are right. I finished my flight from Guyana (SYCJ) to Narita Japan NRT non stop with out a fuel stop with the FS2004 B747-400.
Distance as per FS2004 8054.9nm
Fuel Capacity 57164 gallons
Estimated average gallons per mile burn 9.9gallons
Estimated Total Fuel Burn 79834.5 gallons

Actual total fuel burn 52164 gallons !!
Fuel left 4525gallons
Average gallons per mile burned 6.5gl
Reserve range based on fuel left and fuel burn 696nm.

I kept checking my fuel burn on the trip and slowed down on the last 2000nm of the journey from mach .85 to .82 to see if I would increase fuel economy which improved from 9.9 gallons per mile to 6.5. I am not sure if that is what increased the fuel economy. I know in the real world factors such as winds ,.weight temperature ATC would affect the results or planning so the results could have been way different. I am glad I made it though.

Mandala 499. How would you calculate fuel burn on FS2004 ? By the way welcome to my respected user list I have been meaning to do it for some time. Thanks.
 
FlyboyOz
Posts: 1743
Joined: Tue Nov 21, 2000 10:05 am

RE: FS2004 Calculations Vrs Real World

Tue Oct 18, 2005 6:04 pm

Well...I used a Boeing 747-400 to fly from LHR to JFK. What I had found it odd is that it took only THREE hours to fly between LHR and JFK in FS2004. I couldnt figure out why FS2004's calculation is all wrong. LOL
The Spirit of AustraliAN - Longreach
 
gg190
Posts: 158
Joined: Fri Jan 28, 2005 7:25 am

RE: FS2004 Calculations Vrs Real World

Wed Oct 19, 2005 6:58 am

Quoting FlyboyOz (Reply 4):
Well...I used a Boeing 747-400 to fly from LHR to JFK. What I had found it odd is that it took only THREE hours to fly between LHR and JFK in FS2004.

????? How did you manage this!? Its time calculation has always seemed fairly accurate to me. It certainly isn't as far out as that!
 
mandala499
Posts: 6458
Joined: Wed Aug 29, 2001 8:47 pm

RE: FS2004 Calculations Vrs Real World

Wed Oct 19, 2005 10:46 pm

JAM747,
1. Standardize your flying methods... Consistent policy on climb (like 250kt below 10,oooft, 280 or 300 above, then transition to a Mach number) This way, you'll... (see below)
2. Know your planes.
3. And don't forget how long the ROUTE distance is  Smile

This way, I got familiar with my planes...
Eg: PMDG 737s... on 0.78 - 0.8 cruise...
Type FL300 (figures are total fuel consumption per hour, in tons)
736 = 2.4, 2.2
737 = 2.5, 2.3
738 = 2.6, 2.4

Plus and minus 100 - 200kg per hour depending on load and speed adjustments. At 0.78 the aircraft will give a true airspeed of 450 - 480 KTS..
It'll take the aircraft 1.5 - 2.5 tons to climb to cruise... and it'll take 15 - 20 mins.
500kgs is a safe bet for a descend...
I want 4 - 6 tons fuel when I arrive...

Pile up the numbers above, and you'll get a benchmark figure on how much fuel you need to load and how far you can go and how much payload you can carry... Sure there's an FMC on PMDG 737 but I plan my fuel based on those benchmarks and always end up more or less on my prediction which is "better" than the FMC predictions...

For 767, standardised flying I end up with:
6 tons of fuel an hour if heavy... 5.5 tons of fuel moderate heavy, 5.2 tons or even less when light... Fly a 7hr trip from MTOW and Planned to land with 7.5 tons of fuel remaining and presto... <500kg out...

When you add wind, schedule demands, ATC... it's even more satisfying when you hit the fuel planning right and arrive on schedule  Smile It takes practice and more practice and more practice...

The ultimate freeware addon aircraft that requires good standardised flying by the book and fuel planning is the Project Fokker 100/70... No fuel flow gauge... Nice (and cruel) way to build flying discipline to help with fuel and route planning  Smile Thanks to the comprehensive tables that comes along with it  Smile

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !

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