Ok, another Fuel planner question.. I'm using the 737NG fuel planner, 737-800 selected. I plan a trip from KPIT to KATL, enroute dist almost 500miles (as selected in fuel planner), cruise alt, FL350extra dist to alt: 200headwind: 20payload 44,290 (as read from flight sim)and it gives me an enroute fuel burn of 6,733lbs. (plus additional for alt airport, taxi, and minimum landing)I use FS ACARS, and have the actual fuel usage from lift off to landing. It is over 9,000lbs. My headwind was accurate for the majority of the flight. I use FMC, and fly at the optimum alt. for efficiency, no holds, or unusual routing. I have found this to be fairly consistant with all of the flights where I have used this utility to calculate my fuel. Any ideas why it might be almost 2300lbs off?

Ok.. I noticed on the PMDG manual, the fuel load estimation for the 737/800 shows for a 600nm trip, at FL370, the estimated en-route fuel useage should be around 7300lbs. In actual flight, at 10 miles prior to my top of descent, I had used almost 8,500lbs (more than 1,000lbs over prior to the descent phase). Evidently I am doing something that is causing more fuel useage than what I should have. Fuel planner showed my enroute fuel burn (with wind correction, and pax weight/cargo load calculated) at 7665lbs. Obviously I am doing something wrong in my flight to cause too much fuel useage, but I can't figure out what. I am using VNAV/LNAV mode for my ascent/cruise/descent, and believe to be setting my route/spd/alt restrictions correctly. I am using PATH DES mode for my FMC descent mode.. Any suggestions?

Anyone have any ideas?? Obviously I am doing something to cause more fuel flow than is nessesary, I just can't figure what it could be.

Gear up? Flaps in? Doors closed? :-)Are you flying at optimal altitude?...Cheers,

Thanks for the reply. Yup. Geer/flaps/doors all secure. Yup. Optimum alt. as per FMC. One thing I am trying is changing my cost index. Not knowing what to set it at, I had it at 500. I decreased to 100. We'll see how it goes...

Yup. That's probably the cause500 is very time efficient! Not so fuel efficient though. ;-)I know that real world operations use 25-50 for CI. I bet you that is what is causing you excessive fuel consumption. :-)The higher the CI the more you gain speeding the flight i.e. if you have well payed crews and the like. Low cost airlines use a low CI as they can afford to have their crews longer in the air.Cheers,

You can use the Flight/plane fuel flow data logging in FSAcars change the cost index and see what happens for several values.Jos

Yup, the cost index seems to have an effect. Since changing it to 100, the figures are usually within 1000 lbs of one another. I can probably change to something less (say around 50) as suggested above, and get it even closer.Thanks for all the help folks.Bill

where's the fuel planner utility? In my PMDG file list on the start menu - programs the only thing i have apart from documentation and weblinks is the Load Planner which shows fuel loads according to pax and cargo but nothing about routes/distances?Hope you can point me in the right direction.CheersRick

It is a separate add on utility (3rd party). It can be found on the PMDG web site.

Rick,[a href=http://www.metacraft.com/737NGFP/]Fuel Planner[/a]CheersDavid

500 CI !!!!!! LMAOFYI Virgin Blue usually have CI's around 11 (sometimes up to 16) for fuel economy.From memory Qantas used to use CI's for their 734's of around 32.You will certainly see a BIG difference in fuel economy.

thanks boysRick

You can try to use alternative planner - B737 Fuel Planner.. You can download it on http://www.volny.cz/fs2002/B737FPL/B737FPL.htm. mp