View Full Version : Fuel burn in climb
Talking about boeing 7' series (737, 767, 747).
I looked at their AOM's and it seem that there is no data on fuel burn in climb (only N1 in climb). All there is - for long range cruise control perfomance (http://img359.imageshack.us/img359/7919/cruizeperfomancevl0.jpg). So how climb burn is calculated, especially with taking gross weight into account?
GSLOC
12th Jun 2008, 16:59
Any ideas anyone?
Check Airman
12th Jun 2008, 17:20
Fuel burn will be changing all the way up, so it's difficult to give a fuel flow number. However there are tables that will give total fuel consumption for the climb phase.
GSLOC
12th Jun 2008, 17:58
Where these tables can be found? Neither AOM, nor QRH have them
B737Capt
12th Jun 2008, 23:57
Boeing Flight Planning & Performance Manuel (http://www.b737.org.uk/perf_climb.gif)
Airbus FCOM 2 & 3
:cool::cool:
GSLOC
13th Jun 2008, 00:57
Thank you, that's exactly what i need (at least for 737)! However iam steel confused why it is not published in aom or other related document like qrh or flight crew training manual.
18-Wheeler
13th Jun 2008, 02:01
747 Classic is close enough to ten tonnes from takeoff to top of climb. AS mentioned, the burn varies quite a lot from ground to cruise. Something like 33 tonnes/hr on takeoff up to 13 tonnes/hr for a heavy cruise.
enicalyth
13th Jun 2008, 06:45
I have a set of "norms" for the 744. I can distill these into a spreasheet quite easily.
For the a/c I know a look out the window, figures from the loadsheet and put the two together. Bingo. Yes, you do need some kind of ready reckoner in case one day the gremlin strikes.
I don't need to rehearse the usual caveats. If this will do either post or drop me a line.
GSLOC
13th Jun 2008, 06:47
747 Classic is close enough to ten tonnes from takeoff to top of climb. AS mentioned, the burn varies quite a lot from ground to cruise. Something like 33 tonnes/hr on takeoff up to 13 tonnes/hr for a heavy cruise.
Yes, that's why iam asking. I need exact figures.
enicalyth
14th Jun 2008, 12:58
Exact figures? They don't exist till you've flown it but estimates and rules of thumb can be helpful.
Have a word with your engineering ops dept and they'll explain.
Figures for what BRW, Initial Climb to where, Temp?? Here is one variant of the 744. No noise restrictions, radical departure. [Doesn't happen, EVER].
Anyway try this. Climb to FL330. 'Valid' for BRW 340->400T.
Distance ~ (0.6BRW-110) ISA; (0.6BRW-105) ISA+10; (1.1BRW-245) ISA+20
Time~ (0.1BRW-20) ISA; (0.1BRW-19) ISA+10; (0.15BRW-30) ISA+20
Fuel~ (35BRW-5600) ISA; (35BRW-5200) ISA+10; (50BRW-9500) ISA+20
In case I have mistyped a first guess goes as follows. Say BRW = 386T. Estimates are then 122nm, 127nm, 180nm to T/C at FL330 at ISA, ISA+10, ISA+20 respectively.
Similarly time 19, 20, 28 mins respectively.
Fuel 7910kg, 8310kg, 9800kg which you can work out as being 2.05%, 2.15%, 2.54% of BRW respectively.
In general the smaller the aircraft the higher the %age BRW is burnt in climb but the gross figure naturally is smaller.