Consumption
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Consumption
It came suddently to me today: How big is the consumption for take-off and climb to flight-level - compared to the following levelled flight?
Regarding a typically modern airliner, it is.
Regarding a typically modern airliner, it is.
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Take-off and climb are (almost!?) equalled by the decending in the other end! Sadly I must admit that I never have given this logic a thought before now :-(
However, the consumption of the T/O and climb alone (wich would be most understandable as comparished with the cruise consumption) would be interesting to hear!
However, the consumption of the T/O and climb alone (wich would be most understandable as comparished with the cruise consumption) would be interesting to hear!
Last edited by Flybiker7000; 10th Jul 2015 at 23:56.
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We seldom look at the fuel flow during takeoff. However, a bit of research indicates the specific fuel consumption of a GE CF6 is .354 (lb/hr fuel consumption per lb thrust) at sea level (Exergy Analysis of a Turbofan Engine: CF6-80 (PDF Download Available)). At a nominal 60,000 lb thrust, that would mean a fuel flow of about 9600 Kg/hr. Nominal cruise thrust in a 747-400 is 2500-3000 Kg/hr per engine, depending on weight and altitude. At idle, they burn 500-600 Kg/hr.
A319 at typical weights uses ~ 1,800kgs to top of climb ( mid to upper 30s ) in about 25 minutes. The descent typically takes 30 minutes and uses ~ 600 kgs.
The cruise uses about 2,000kgs/hour.
This "rule of thumb" is pretty accurate in my experience as a gross check on the computer flight plan.
The cruise uses about 2,000kgs/hour.
This "rule of thumb" is pretty accurate in my experience as a gross check on the computer flight plan.
