777 Fuel Index Question
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Join Date: Nov 2009
Location: Somerset
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777 Fuel Index Question
To any 777 trainers / people that understand it...
Why do you enter the MACTOW into the CRZ CG above 98 tonnes of fuel, rather than MACZFW. I understand its something to do with the fuel index but its unclear.
Also does it effect the optimum altitude in the FMC?
Thanks in advance!
Why do you enter the MACTOW into the CRZ CG above 98 tonnes of fuel, rather than MACZFW. I understand its something to do with the fuel index but its unclear.
Also does it effect the optimum altitude in the FMC?
Thanks in advance!
Join Date: Aug 2007
Location: canada
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This is done because the default is very conservative. You'll recall that an a/c with an aft c of g can climb a bit higher than one with a forward c of g. The entry you're making is intended to refine the computation in the FMC. Otherwise your FMC computes too low a cruise regime and your trip fuel suffers.
Why this couldn't have been built in is another question.
Why this couldn't have been built in is another question.
