How much fuel (kerosene) does a 747 burn?

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When the gas crunch of the '70's got underway, a friend who was in a squadron (I was at NAS Miramar then) told me what a Phantom could hold full fuel load. Whatever it was we estimated that if you figured that in gas gallons instead of pounds of JP it would operate my (then) 440-6 Roadrunner a couple of years. Just one mission. And just one aircraft
 
67Dart273 said:
When the gas crunch of the '70's got underway, a friend who was in a squadron (I was at NAS Miramar then) told me what a Phantom could hold full fuel load. Whatever it was we estimated that if you figured that in gas gallons instead of pounds of JP it would operate my (then) 440-6 Roadrunner a couple of years. Just one mission. And just one aircraft
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It's been too many years, so i have forgotten how many gallons of JP-4 a Phantom holds internally. Depending upon the model, figure on 2,000 gallons, but if all 3 external tanks are hung, the center held 600 gallons, and the outboard tanks held 300 gallons each.
Lotsa "gas" to keep them up in the air, for a mission before they run low, to meet up with a tanker, for in flight refueling.
 
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Yes, but a 747 can run at that throttle setting for hours and hours at a time, how long will that nitro burner run for before failure?
 
If you want to really boil this down, how much mass are you moving over those distances for that rate of consumption?
 
Wouldnt the airliner be traveling a 1/4 mile just over a secend burning just over 1 gallon.
Unlike the top fuel car burning about 40 gallons a 1/4 mile taken about 3 x longer.

I dont see the same rate ?
 
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I think it is a full throttle rate in which a jet airliner doesn’t do as far as I know. It will fly at 3/4 - 7/8 of full throttle during its flight time. Full throttle at the full flight time isn’t done.
 
grimreaper said:
One of the top fuel facts from the internet.....
Under full throttle, a dragster engine consumes 11.2 gallons of nitro methane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced.
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from the internet..... Let'd do some math here: 11.2 gallons per second. top fuel run is ~5 seconds and the associated idle time. You gonna tell me they hide a 55 gallon drum of nitro in that rail?
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Then you can look at 55 gallons going into 900 Revs, yeah. 7.82 oz per revolution, or about an oz of fuel per cylinder per revolution? Show me the pump. Maybe it was 11 gallons per minute. Here is a 355cid chevy on 100 nitro. "SBC consumes 567.53 cfm @ 6500rpm which is 42.64 pounds of air and now at 1.7:1 ratio for nitromethane is 25.08 pounds of fuel PER MINUTE
 
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747 flies at about 570 mph or .15 miles (792 feet) per second. It burns ~5 gallons per mile (6.5 seconds) so it burns 1.3ish gallon every second. Sometimes math is an inconvenient truth.
 
Another B747-400 estimate: 870,000 lbs accelerating at 9.1ft/s² is roughly 70,000 HP on takeoff estimating the weight and acceleration of the beast. There was a Top Fuel drag spreadsheet that was posted in 2014 that claimed "You get about 115 horsepower for each gpm (gallons per minute) of 90 percent nitro you burn" and if you factor in the 10,100 HP the graph was based on and the ~3.7 sec run it was looking at...you get 87.82 GPM or 1.46 gallon per second...BUSTED! Sure the Antron Browns car burns more fuel per second (all 4 of them), but it aint making 70,000 horsepower either. OK, bedtime......
 
HOWEVER, you don't want to focus on just MPG (or in this case gallons per mile). I'm pretty sure that airlines compute their fuel by something like 'pounds of fuel per passenger mile'. So a 400 passenger jet that got lousy fuel economy could be more economical per passenger for a given trip than a 125 passenger plane that was much more efficient.
 
a 80,000 lb big truck burns 1800 lbs or 240 gallons of diesel every 1200 miles or so at 65 mph average, equates to 5 mpg.
 
In a good note, the plane does transport 100's of people for that fuel rate, the dragster and the semi truck, not so much!!
 
I have a good friend who flew f4 phantoms in 68 - 69 he told me with a full load of weapons they would put a little over a half a tank in for takeoff using full power plus afterburner it would just get him to 15000 ft to meet up with the tanker to fully fuel . he said it took a serious amount of fuel to get that bird in the air .
 
cosgig said:
In a good note, the plane does transport 100's of people for that fuel rate, the dragster and the semi truck, not so much!!
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big truck hauling 48,000 lbs of consumer products of some sort, if you got it, a truck hauled it,..probably 2 to 5 trucks in all on most stuff! dot dont allow people to be used as freight! theres bus's for that.
 
rumblefish360 said:
I think it is a full throttle rate in which a jet airliner doesn’t do as far as I know. It will fly at 3/4 - 7/8 of full throttle during its flight time. Full throttle at the full flight time isn’t done.
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You are correct. Typically, a jet airliner doesn't even use full throttle at take-off. Sometimes transatlantic aircraft might use full throttle at T-O. (They use reduced power to lessen the strain on the engines. Thrust values are calculated for each take-off). There are a vast amount of throttle (power) settings for aircraft based on type engine, pressure altitude, etc. 90% power is fairly common.
 
jimjimjimmy said:
I have a good friend who flew f4 phantoms in 68 - 69 he told me with a full load of weapons they would put a little over a half a tank in for takeoff using full power plus afterburner it would just get him to 15000 ft to meet up with the tanker to fully fuel . he said it took a serious amount of fuel to get that bird in the air .
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That is true. Although it was a great plane, it was heavy and about as aerodynamic as a brick. The F-4 is proof positive that with big enough engines, just about anything will fly fast.
 
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