Santiago,Once again thanks for explaining this in great detail this has helped me in planning my flights in greater detail.May I ask do you use vatsim for your airtraffic control or radar contact?Natalie French

SantiagoAre you a real pilot?Natalie French

Real ATC & aircraft dispatcherSantiago

Real ATC & aircraft dispatcherSantiago

Santiago,Can you tell me is the average cost index 25 for the 737-700Natalie French

Cost index will vary between airlines. There are a bunch of airline CI's posted in this thread: http://forums1.avsim.net/index.php?showtopic=284265

Cost index will vary between airlines. There are a bunch of airline CI's posted in this thread: http://forums1.avsim.net/index.php?showtopic=284265

Thanks for your HelpNatalie French

Thanks for your HelpNatalie French

This is a good discussion, Natalie. You're getting to some of the finer points of the system. You may already do this, but make sure you also have a handle on some of the basics, like determining how long you can hold at your destination before diversion is necessary.

Hi Natalie,From experience I have found that as a rule of thumb, the B737NG 800's use about 3,300 Kg of fuel an hour. So my my calculation would be like this:Dist 737 nm at 400kts (allowing for a slight headwind) = 1 hour 50 minutes at 3,300 kg/hr = 6,080 kg + fixed reserve of 2,400kg +Alternate fuel 1,600 kg + holding 1,500 kg and 250 kg for taxi comes to 11,830 kg or 26,000 lbs.I use a cost index of 12.Hope that helps.Have fun. :( Neil Bradley

First of, the B738 uses a cost index of 25-40 depending on Airline, Ryanair use CI30. I have done the EGKK-LEPA hop many of times offline and online (VATSIM) and i use 25%-35% of fuel

First of, the B738 uses a cost index of 25-40 depending on Airline, Ryanair use CI30. I have done the EGKK-LEPA hop many of times offline and online (VATSIM) and i use 25%-35% of fuel

So when my flight plan says CI60, my dispatcher screwed up? :(

You can't make a connection between a cost index and an airline or aircraft type.Each flight could have a different cost index. They are varied to accommodate situations with complex variables like cost of fuel at destination, cost of arranging accommodation for pax missing their connection, headwinds, crew scheduling issues etc. Things that are really beyond flight simulation.For simulation purposes just pick a cost index that suits your purposes, it won't make your flight any less realistic. A higher one will get you there faster and burn more fuel, a lower one the opposite.

This is a good discussion, Natalie. You're getting to some of the finer points of the system. You may already do this, but make sure you also have a handle on some of the basics, like determining how long you can hold at your destination before diversion is necessary.

Hi spin737Thanks for the input, Can you please tell me how to work out head winds???Many thanks Natalie French

So when my flight plan says CI60, my dispatcher screwed up? :(

Not even close to the top end, you can put a Cost Index range of 0-500 into an NG, 0-200 for Classics 737s.In practical terms, 0 gives minimum fuel usage, 500 will take the aircraft up to Vmo in the climb and cruise, and put the descent up to a maximum speed of 330 knots. Since some regard 'time as money' too, the CI will depend on where the airline's product is placed in the pecking order of quality versus value. An airline which flies a 737 on a trip likely to have many business travelers on board is likely to view their CI choice as a means to ensure that they can arrive on schedule, which for that particular product may be regarded as of equal importance to saving a few quid, since the ticket prices may be pitched to compensate for increased costs.For us simmers, it's not a big deal, but it is handy to know all that if you want to simulate such business choices.Al

Hi spin737Thanks for the input, Can you please tell me how to work out head winds???Many thanks Natalie French

Well, that'd be with some sort of wind calculator. An E6B affair or something online. This looks pretty good: http://www.luizmonteiro.com/Wind.aspx Are you wondering about doing this on the ground with the winds aloft forecasts or in flight?With the fancy FMC, all you need to do is put in the winds for each point from the the computer flight plan or from the winds aloft forecasts that a few of the dispatchers gave you the links to. On PROG page 2, you can then see the headwind component.When I'm preflighting the FMC, after I've verified the legs, I enter the RTE DATA (winds). No calculations necessary to find out the headwind.

If you want to get into fancy wind predictions for fuel planning in FS, then you can use something such as Active Sky Evolution or the ACARS device in Flight Keeper to get winds aloft reports along your routing. Then you could perhaps use Aerosoft's Flight Calculator (which is great by the way, since it can pull data from FS via FSUIPC), to plan things. Or, if you preferred to do it the old school way, you could whip out your trusty E6B calculator (which has probably been gathering dust at the bottom of your flight bag from your PPL days) to work out the correct drift headings, however, as Spin points out, the FMC should fly offsets properly so long as it knows the drift, and it will usually know that from the ground track it gets via GPS data, or if you have put in the winds aloft data.There are one or two freebie E6B simulators you can find online, but these days, if you wanted to emulate what most pilots would use, the aforementioned Aerosoft Flight Calculator is probably a better shot, since it emulates a gadget that most savvy pilots probably have bought for themselves. That said, many airline pilots do still keep an E6B in their bags too, since there is no way the batteries can run out on a traditional cardboard E6B, the worst that can happen to it, is if you spill coffee on it, although if you do that, it would probably match the new PMDG's NG's level of cockpit cleanliness LOLAl

I really enjoyed this thread. It sure helped in understanding fuel planning. I hope some are still following along, esp. Santiago.My question is in reference to the fuel consumption and wind direction. In the examples given, there was no calculation for wind speed nor direction. Does this mean it is not necessary to consider it? If it should be figured in,how would that affect fuel quantity?Jim D.