Remember the HOWGOZIT?
I love using my HOWGOZIT?
Better on Long Haul than short haul as you may be devoid of time.
I lamenated mine and use a chinagraph on it then rub out the marks after use, with a wet finger.
This is a nice way of determining a leak before it becomes apparent in other areas.
I know you know, but for those who may have missed it in their studies;
draw a line vertically in the left hand column of A4 Landscape not Protrait -
and another line (the horizontal axis along the bottome of the graph to be . .
Left hand line (vertical left margin is your fuel in ,000kg or lbs if you are using lbs of fuel . . .
Along the bottom line write your distance in NM or KM if you must . . . (!)
the top of the left line is your total fuel on board minus taxi, takeoff, clb, or not if its a long step . .
in the cruise, soon, hopefully,
Draw a nice straight line from the fuel you have got at TOC all the way down to . .
Dest - at which point you intend to arrive at Dest with your pre-planned Dest fuel and all its reserves and all that.
As you proceed in your flight along track, check FOB against miles gone (along the bottom line in NM)
Cross the two points from the fuel amount FOB where it intersects the NM gone DIST and where the vertical and horizontal intersect draw a little asterisk or a tiny cross "x"
All along your route, your Straight line you drew diagonally from fuel line to Dest will have the little "x"s on it, above it or below it. If below it, of course, you are using more fuel than pre-planned if above the diag line then you are using less fuel for that geographical position. Removing the obvious considerations en-route such as head wind / tail wind or into the teeth of a Jestream, temp, etc., and all the rest of it - you can readily determine if you are illogically using too much fuel.
If consumption is high `despite` taking into consideration the above calcs and wind then - chances are you have a leak or a very thirsty engine. the latter may be determined by your GFF - of course.
You could also get dweeby and simply determine SFF by dividing total GFF by the Groundspeed to give you Kg per ground NM..... Kg/gnm or... lbs/gnm if you have a President.
Last edited by Natstrackalpha; 2nd Jun 2012 at 14:34.