FSAirlines

We have a number of different 747 types in our airline fleet and I'm trying to generate some useful fuel planning data for each individual type, which will be shown in following posts.

The basic route for generating fuel useage and performance will be of leg ranges of 500, 1000, and 1500 nm using the following criteria:

Cruise at M0.83 at FL350
Climb at 280 IAS and 80%N1 under ATC control to cruise altitude (235 IAS to FL100)
Initial fuel loads will be full pax/cargo and using real weather.

Obviously real weather will have an impact on fuel useage, but should be reasonably consistant.

747-200M

With 2 flights so far the following seems to be true:

Taxi fuel useage @ 5750 kg/hr
climb fuel useage @ 12750 kg/hr
cruise fuel useage @ 6750 kg/hr
descent fuel useage @ 4800kg/hr

Please be aware that the descent is from top of descent to touchdown.

747-300M

With 11 flights (all using real weather) so far the following are average fuel consumption figures:

Taxi fuel useage @ 6000 kg/hr
climb fuel useage @ 13650 kg/hr
cruise fuel useage @ 6250 kg/hr
descent fuel useage @ 5000kg/hr

Please be aware that the descent is from top of descent to touchdown.

As I use FSNav to generate my routes, using the above seems to work fine, but dont forget to add taxi and SID/STAR fuel. In the routes I have flown, this would equate to just about another 4 tonnes with no safety margin, so I'll be adding a total of around 10 tonnes to suggested fuel load in FSNAV. This has been seen to work well leaving between 4 and 7 tonnes at gate. The most economic range against time looks to be around 1000nm.