help needed c130 boys
Thread Starter
Joined: Oct 2007
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From: UK
help needed c130 boys
have to find out how much EXTRA fuel a C130H would use when flying a 2.5 tonne weight 825 miles as opposed to one that was 2.5 tonnes lighter.
Now this isnt for a bet this is real. Bear in mind I am now a civvie and the only thing I know about herculeses is that they are horrible, the heating is either furnace hot or not on and I have been sick in them loads of times.
the flight would be over water if that helps in nasty weather too.
Now this isnt for a bet this is real. Bear in mind I am now a civvie and the only thing I know about herculeses is that they are horrible, the heating is either furnace hot or not on and I have been sick in them loads of times.
the flight would be over water if that helps in nasty weather too.
Last edited by oldbooty; 31st October 2007 at 11:10. Reason: not clever enough
Joined: Jul 2001
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From: The dark side...
Hmm, a Hercules, over water for 825 miles carrying an extra 2.5 tonnes - you're not based in South America with eyes on some British territory are you? I've got your number oldbooty or should that be El Booty or even Antigua Botín? (thanks Google)
Joined: Jan 2004
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From: Far West Wessex
If you're asking for the weight in tonnes, shouldn't you have the range in km? And I don't think that's the plural of Hercules... though it's one of those tough ones, a bit like mongoose because you know that neither mongooses nor mongeese sounds remotely right, which is why most of us pros stick to "C-130s" or "Fat Alberts" and there is not a proper Latin plural for Hercules (he was Heracles in Greek, like the HP.42... by the way, did you know that Imperial Airways had a Hercules and a Heracles?) anyway.
Thread Starter
Joined: Oct 2007
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From: UK
Schlong
I am impressed by your geographical knowledge and powers of deduction.
However your suspicions of nationality are a country mile out (although it is a south american plane)
the aircraft will be going anyway but i need to know how much fuel it will use with our load on top of what it would have used without it.
I appreciate this is an inexact science (I can hear the flight engineers and loadies getting outraged as I type) but a round about figure would be fine.
Ive jumped out of em ive been sick in em ive even broken my ankle on the tarmac at lyneham climbing out of one. I have never needed to know how much it would cost to fill it up at Asda before now. but now I do.
btw shlong I seem to remember a few miserable months trying to get back a british territory some 25years ago. and if we want to get technical the Antarctic treaty places all territory claims aside until 2041.
your help gents would be appreciated if you can give it
I am impressed by your geographical knowledge and powers of deduction.
However your suspicions of nationality are a country mile out (although it is a south american plane)
the aircraft will be going anyway but i need to know how much fuel it will use with our load on top of what it would have used without it.
I appreciate this is an inexact science (I can hear the flight engineers and loadies getting outraged as I type) but a round about figure would be fine.
Ive jumped out of em ive been sick in em ive even broken my ankle on the tarmac at lyneham climbing out of one. I have never needed to know how much it would cost to fill it up at Asda before now. but now I do.
btw shlong I seem to remember a few miserable months trying to get back a british territory some 25years ago. and if we want to get technical the Antarctic treaty places all territory claims aside until 2041.
your help gents would be appreciated if you can give it
Joined: Feb 2005
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From: NW FL
Oohh, oohh - lemme give it a shot: The square root of !!!!-all!
I don't do metric, so had to convert to pounds (as all proper alberts are delivered - despite the RAF's decision to subrogate themselves to the movers whims) & using my pilot math (KG x 2 + 20%), I came up with round about 6K lbs which means very little in the grand scheme of things...
I assume you're trying to figure out your share of the petrol, eh? Charter air doesn't typically work that way. An easier way would be figure entire cargo weight by operating costs & then figure your percentage of the cargo weight (again, true charter cargo doesn't work this way, but close enough...)
I don't do metric, so had to convert to pounds (as all proper alberts are delivered - despite the RAF's decision to subrogate themselves to the movers whims) & using my pilot math (KG x 2 + 20%), I came up with round about 6K lbs which means very little in the grand scheme of things...
I assume you're trying to figure out your share of the petrol, eh? Charter air doesn't typically work that way. An easier way would be figure entire cargo weight by operating costs & then figure your percentage of the cargo weight (again, true charter cargo doesn't work this way, but close enough...)
Thread Starter
Joined: Oct 2007
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From: UK
oddly its not cost its the carbon footprint!
FFS Gotta keep the bunny huggers happy!
but 6K sounds good to me.
Thanks for that
I'll eat a penguin for you
FFS Gotta keep the bunny huggers happy!
but 6K sounds good to me.
Thanks for that
I'll eat a penguin for you
Last edited by oldbooty; 31st October 2007 at 14:41. Reason: cos I am a mlaaring panhead
Joined: Apr 2000
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From: Chigley
6000 lbs !
Thats far too much extra; You could fly for an extra hour and a bit with that. Divide it by 10 and round down to be more realistic.
500 lbs is an over estimate.
Work on an extra 200 lbs per hour
Thats far too much extra; You could fly for an extra hour and a bit with that. Divide it by 10 and round down to be more realistic.
500 lbs is an over estimate.
Work on an extra 200 lbs per hour
Joined: Oct 2005
Aviation Qualifications: Military
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From: UK/Philippines/Italy
It has been 20 yrs but:
8/10ths of sweet FA.
The fuel calculation for the flight will be done on distance to be flown, diversions, weather etc etc. This results in an APS weight. The remaining weight up to MTOW (or whatever other limit is involved) is available for load (pax/freight)
All that said, the bean counters in commercial aviation often use a 3% figure (not standardized, this) for the cost of hauling fuel that will not be burned.
This takes into account slower take off, longer to cruise etc. Or so they say. Think of a truck with 20 MT on board. It will burn x amount of fuel on a run. Add 5 tons and it will burn a bit more for hills, moving off etc.
Using this:
2.5 MT = 5500 lbs
3% = 165 lbs
8/10ths of sweet FA.
The fuel calculation for the flight will be done on distance to be flown, diversions, weather etc etc. This results in an APS weight. The remaining weight up to MTOW (or whatever other limit is involved) is available for load (pax/freight)
All that said, the bean counters in commercial aviation often use a 3% figure (not standardized, this) for the cost of hauling fuel that will not be burned.
This takes into account slower take off, longer to cruise etc. Or so they say. Think of a truck with 20 MT on board. It will burn x amount of fuel on a run. Add 5 tons and it will burn a bit more for hills, moving off etc.
Using this:
2.5 MT = 5500 lbs
3% = 165 lbs
Joined: May 2005
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From: Lincs
From some first principles and a bit of Googled data.
Fuel is burned to overcome Total Drag, of which
Lift Induced Drag is,say, nominally 30% of Total Drag.
So, 30% of fuel burn is proportional to AUW.
Herc fuel burn (guessing) 5,500 lbs/hr?
Sector time roughly 2:30hrs
Total fuel burn 13,750 lbs
30% of this is 4125 lbs.
Nominal AUW, say, 165,000 lbs
So variable Fuel burn per lb of AUW = 4125/165,000 = 0.025
So Delta fuel burn for 2.5 tonnes (5,500 lbs) = 5,500 x 0.025 = 137.5 lbs
Different route but same ball park as Larssnowpharter above - must be right then!!!
Fuel is burned to overcome Total Drag, of which
Lift Induced Drag is,say, nominally 30% of Total Drag.
So, 30% of fuel burn is proportional to AUW.
Herc fuel burn (guessing) 5,500 lbs/hr?
Sector time roughly 2:30hrs
Total fuel burn 13,750 lbs
30% of this is 4125 lbs.
Nominal AUW, say, 165,000 lbs
So variable Fuel burn per lb of AUW = 4125/165,000 = 0.025
So Delta fuel burn for 2.5 tonnes (5,500 lbs) = 5,500 x 0.025 = 137.5 lbs
Different route but same ball park as Larssnowpharter above - must be right then!!!
Joined: Feb 2000
Posts: 612
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From: UK
Many, many years ago, when I was but a puppy, I used to do loadsheets and the APS weight was the weight of the aircraft with all the galley stuff, pilots and hosties but no load, i.e. an empty "Aircraft Prepared for Service", with just the FRT,SLF and fuel to pour in. We'd start with an APS weight and then add the load to get a Zero Fuel Weight (probaly all called "mass" now in this PC, Eurocentric world) and then subtract that from the MTOW to get a max fuel load and hope it got us there! (No, seriously we weren't really that gash).
I remember asking to put a car on an empty leg from Lye to sonewhere in the UK and asking how much it would add to the burn and all and sundry said negligable but it was only a Nissan estate so I don't think it was 2.5MT.
Do I remember wrong?
Doc C
I remember asking to put a car on an empty leg from Lye to sonewhere in the UK and asking how much it would add to the burn and all and sundry said negligable but it was only a Nissan estate so I don't think it was 2.5MT.
Do I remember wrong?
Doc C