Fuel Calculation

[JetBlueInflight]

I was wondering what some people use to calculate fuel for a flight. I usually do like a rough estimate or just fill up the tanks, but I know
that is not really economic. What can I do to calculate the fuel I will be using at altitudes and such so I can keep the weight down on my
aircraft (and maybe make some money off of taking some more baggage)??

[poden]

I basically know my plane's maximum range, and just put less fuel on board based on what fraction of that range I'll be flying. Then I figure in a
little more for a reserve. Pretty rough process, but I usually do OK. Only got the reserve penalty a couple of times.

[JanniCash]

I mostly fly the FFX B737-200 ADV by Eric Cantu. Based on the abbreviated flight planning charts for the 737-200 I wrote myself an HP-48 utility
program that, running in the HP emulator, does the calculation for me.



It only supports this one plane at the moment. I can post the HP-48 source code if someone is interested.


Jan

[lcrane]

First, I figure out what my average cruise speed and average fuel burn for type of aircraft at a specific altitude. This can be found on the flight
report after you fly once with that aircraft. Different altitudes will have different cruise speed and fuel burns so keep track on a chart the
differences. Second, I calculate the distance from point A to point B and the time it takes to get there using my average cruise speed. Next, I add
one hour onto that time for my reserve. FAA only requires 45 mins but FSP is happy when I give it a little more fuel. (Actually, FAA requires
fuel from point a to point b to alternate airport plus 45 mins. But we're not flying for FAA. This is for fun) Finally, I calculate the fuel I'll
use given the time I calculated. I convert this to lbs and there you go. Why do this? Because weight is money and the less extra fuel you have the
more cargo you can take and the more money you can make. Extra weight will also slow the aircraft down a bit and if you're going to carry around
that extra weight you might as well make it earn it's keep.(aka. cargo) I'd recommend getting a flight computer from your local flight school or at
http://www.sportys.com/acb/showdetl.cfm?...&CATID=171. They cost about $12 and if you decide to take lessons for real, you'll
need one. I got mine in 2000 when I starting taking lessons and had it ever sense. It's portable and never needs to have batteries replaced. :D It's
like a circular slide rule if you've never seen one and I and other pilots here on the forum can show you how to use it if you need any help. When I
fly for real it gets more complicated then this simple method I showed you (I calculate fuel burn climb, fuel burn cruise, fuel burn descent and
time for each) but it'll get you real close to what you want.

[JetBlueInflight]

But how do you take into consideration the weight of your a/c? In other words, it will obviously be different if I'm flying the a/c empty and if I
have the belly full.

I basically only want to make the basic calculations. I think FSPax makes a difference between fuel burn at different altitudes, but I don't
think it takes into consideration wind speeds over different areas and so on and so forth so no need to figure that out.

Do you just fill your a/c to the max TO weight?

[michael]

i do it the simple way!

Look in the kneeboard!

[lcrane]

JetBlueInflight wrote:
But how do you take into consideration the weight of your a/c? In other words, it will obviously be different if I'm flying the a/c empty and if I
have the belly full.

I basically only want to make the basic calculations. I think FSPax makes a difference between fuel burn at different altitudes, but I don't
think it takes into consideration wind speeds over different areas and so on and so forth so no need to figure that out.

Do you just fill your a/c to the max TO weight?

I usually fly a route with fuel maxed out. For example, I would fly the King Air from IWA to RNO with as much fuel as I can carry. Note my fuel
consumption and altitude from the flight report. I fly that route at 29000. This gives me my base data. I then do my fuel calculations based on
that. I adjust my data as I fly more routes until I feel confident about my data.

Actually, FSPax only looks at the fuel flow at the moment and calculates the time remaining based on how much fuel you have left in the tanks. Fuel
flow is affected by the altitude.

You're right. Keep it simple at first. You may want to just do a long flight and see what you burn and then add on hour on that. Try the flight
again and see if you were right. Then try a different flight and see if you educated guess was right. There's also lots of software to use in MSFS
to calculate for you. ( I'm currently working on my IFR rating and my instructor won't let me use any electronic devices to calculate. He took my
palm away during a flight to simulate my batteries going dead. I didn't like it at the time but, after some thought, realized I was being trained
for when bad things start to happen when flying and needed to get my brain ahead of the airplane like when you're in the soup, gauges stop working,
electrical goes out, and palm dies. You're left with limited gauges, pencil, paper, charts, flight computer, and your training. That gets the heart
going. :D ) I just showed you a simplified way I do it when I fly. You can make is as simple or as complicated as you want. Remember to have fun.

Finally, if you want to be really challenged and have a flight computer, the back side of the flight computer can calculate the course correction
for winds aloft. It would tell you how much the winds are pushing you off course and affecting your speed.

Keep it simple to start and add difficulty as you want. I just showed you the way I do it. And I like math...so there you go. I've been playing MSFS
sense version 2 on the Macintosh and I played a version in the 80's on the apple IIe but I don't remember if that was Microsoft or not.

[Leftcoaster]

Fuel management can be an interesting exercise in propliners and first-generation jets. FsP only makes you pay for the fuel used and
not the fuel loaded so it provides no incentive to plan carefully and does not penalize the user for buring fuel just to carry fuel. When I fuel
plan in a propliner I use this procedure, with all flight planning done on paper.
Example DC-6B 800nm flight
Average TAS incorporating significant headwind = 240kts x .85 = 204 kts
Enroute time = 800/204 = 3.9 hours x 2200 lbs/hr = 8580 lbs
Diversion Reserve = 1 hour x 2200 lbs/hr = 2200 lbs
Holding Reserve = 45 min x 1600 lbs/hr = 1200 lbs
Emergency Reserve = 45 min x 2200 lbs/hr = 1650 lbs
Total = 13630 lbs
These calculations encorporate runup, taxi, takeoff and climb fuel and are independent of final cruise altitude.

Early jets are a bit different since a Boeing 707-120 can burn some 11,000 lbs/hr during the climb to cruise altitude.
Example Boeing 707-120 800nm flight
Average enroute TAS = 450 kts
Flight time = 800/450 = 1.8 hrs
Cruise altitude = 30000 ft, time to alt = 20 min
Cruise = 8600 lbs/hr = 15480 lbs
Climb = 11,000 lbs/hr = 3630 lbs
Startup, taxi, T.O. = 1200 lbs
Diversion Reserve = 8600 lbs
Holding Reserve = 6450 lbs
Total = 35360 lbs
Note that calculating the climb fuel seperately automatically provides a reserve in case of significant headwinds. Also the Boeing burns
almost three times as much fuel but gets there in half the time with more than twice as many pax. In 1959 aviation kerosine was a
lot cheaper than 100+ octane AVGAS. It's easy to see why propiners were replaced by jets so quickly during the 1960's although FsP
does not reproduce these economics particularly well.

As can be seen on this thread, fuel planning can be as simple or as complex as you like. Enjoy.

[JanniCash]

FsP only makes you pay for the fuel used and not the fuel loaded so it provides no incentive to plan carefully and does not penalize the user
for buring fuel just to carry fuel.

Which differs from the real world only by timing. Even if you always top off the tanks, you can never put in more than you burned during the last
flight. You only pay for the fuel burned.


Jan

[lcrane]

JanniCash wrote:

FsP only makes you pay for the fuel used and not the fuel loaded so it provides no incentive to plan carefully and does not penalize the user
for buring fuel just to carry fuel.

Which differs from the real world only by timing. Even if you always top off the tanks, you can never put in more than you burned during the last
flight. You only pay for the fuel burned.


Jan

You're right. But carrying around unburned fuel (less reserve) is wasted weight. And wasted weight is lost revenue. I'd rather have the weight pay
me some cash rather then sit in my tanks taking up space. In my opinion, the perfect fuel calculation is when I land and shut down and have only my
reserves remaining. That means all my weight brought in money. I haven't been able to do that yet but that's my goal.

[JanniCash]

lcrane wrote:
You're right. But carrying around unburned fuel (less reserve) is wasted weight. And wasted weight is lost revenue. I'd rather have the weight pay
me some cash rather then sit in my tanks taking up space. In my opinion, the perfect fuel calculation is when I land and shut down and have only my
reserves remaining. That means all my weight brought in money. I haven't been able to do that yet but that's my goal.

Yes, and as far as I know FS9 does give you the penalty of higher fuel consumption for higher weight of the aircraft, for which you will have to pay
the fuel price in FsP. So there is a point in doing it right and as far as I can see this is as real as it gets.

See my earlier post. I indeed prefer to calculate it even considering en-route winds. A 737-200 flight is planned perfect if (without alternate
destination) you have 5500 lbs of fuel on touch down. Unfortunately, that usually isn't your overall average fuel flow for an hour, so you have to
have more than that to avoid FsP complaining. And FsP will still give you a penalty for low fuel if that was caused by a go around (which I think that
fuel reserve exactly was meant for). So FsP actually forces me to carry useless fuel around.


Jan

[kjevans]

Here is an option, a flight calculator from Aerosoft.

http://www.aerosoft.com/cgi-local/ca/ibo...50,DF02117

[flameout]

Here is a simple formula to calculate fuel load:

A quick and easy method to determine fuel load is (“Distance to Destination in NM" / “Total Range in NM”) +15% Total Fuel Capacity =
Fuel Load.

For example: range to destination is 400nm, total fuel capacity is 8,090 US gallons, and the total range of the B727-200 is 1,930nm -
Therefore:

(400 / 1930) + 0.15 = 0.357 of the total fuel capacity of 8,090 US gallons – or about 2,888 US gallons loaded for this flight. Strong
headwinds aloft will require more fuel, tailwinds a little less.

flameout

[JetBlueInflight]

You're right. But carrying around unburned fuel (less reserve) is wasted weight. And wasted weight is lost revenue. I'd rather have
the weight pay
me some cash rather then sit in my tanks taking up space. In my opinion, the perfect fuel calculation is when I land and shut down and
have only my
reserves remaining. That means all my weight brought in money. I haven't been able to do that yet but that's my goal.

Well, If you fly continuously like I do, then it's realistic because like in real life, the fuel left in ur tanks can be used for the next flight. But
like we say, fuel is weight, and weight can be revenue......if it's not fuel, of course. No reason to flood your weight with fuel when it could
be bags. Also if you really wanna be realistic, on larger jets you can calculate the max landing weight. As much as that is not a penalty
here for landing abover your max landing weight, in real life you don't want to be left circling above the airport to burn excess fuel so you
can land.

( I'm currently working on my IFR rating and my instructor won't let me use any electronic devices to calculate. He took my
palm away during a flight to simulate my batteries going dead. I didn't like it at the time but, after some thought, realized I was being
trained
for when bad things start to happen when flying and needed to get my brain ahead of the airplane like when you're in the soup, gauges
stop working,
electrical goes out, and palm dies. You're left with limited gauges, pencil, paper, charts, flight computer, and your training. That gets the
heart
going. :D )

HOW DARE HE!!!!!!!!!!!

[JetBlueInflight]

Arright, so here's the deal.....

I downloaded the Flight Calculator from Aerosoft. I have it able to connect to FS so I know it can access some information from the game
itself. I have the ability now to make some calculations now, I just need to know how to do it.

Now, from the game, I can get my payload (including my ZFW from FSPax). I can get the distance and cruising altitude from my flight
plan. As far as WX is concerned, I guess that is something the Calculator can pick up automatically from the game or maybe I have to
look that up on the internet (as I fly with actual weather updated every 15 mins).

Now, I'm sitting at the gate ready to go with my eyes shut for a power nap while the plane is boarding when the ramp guy enters the
cockpit, wakes me up, and asks me how much fuel I want. What do I tell him??

If anyone has this calculator or uses a flight calculator for these purposes, please explain to me how you go about getting this answer.