Re: Delta fuel / delta payload

Date:         12 Oct 98 00:02:27 
From:         "Wayne" <waynesp@ozemail.com.au>
Organization: OzEmail Ltd.
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If it's any help Thomas, a rule of thumb I use for the B747(classic)is:you
will burn all of your additional fuel in 28hrs. ie. on a 7hr flight if you
add 1000kgs to flight planned fuel(assuming ZFW remains as planned),you will
arrive at destination with only 750kgs.Obviously this applies to aircraft
gross weight increases.So on a 9hr flight,if I needed an additional 5000kgs
to be avbl at destination to cover say,a 30 min holding req,I would load an
additional 6700kgs for departure so as to arrive with 5000kgs.
I was taught this many years ago by an old bold pilot and it seems to tie
with info provided on the computer fuel plan.On every flight plan I use info
is given on changes to burn corresponding to LMC's to aircraft gross weight.
ie."additional fuel used xxxx with every 1000kgs increase/decrease in
aircraft gross weight.
I must stress this is ONLY rule-of-thumb,handy for working out rough figures
and expectations.

Now,before you guys out there jump up and down about using rules of thumb,let
me make it clear..  When accurate data is presented ie.on the fuel flight
plan,that is to be used.

--
Kind regards
 Wayne