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>This reasoning was based on the assessment that the cost of fuel wasn’t that high, but the service forgot that B-52s are voracious users of air-to-air refuel-

>This reasoning was based on the assessment that the cost of fuel wasn’t that high, but the service forgot that B-52s are voracious users of air-to-air refuel- ing. By the time the gas comes out of a KC-135 tanker’s boom, the delivery cost has increased by a factor of 15 How is this kind of oversight even possible? Also, this is the crap that got copied onto my clipboard when I tried to copy that quote: Read more: http://www.airspacemag.com/flight-today/b-52-just-keeps-flying-180953933/#ixzz3V90kF6sx Read more: http://www.airspacemag.com/flight-today/b-52-just-keeps-flying-180953933/#2mI866OqRKfEWivD.99 Save 47% when you subscribe to Air & Space magazine http://bit.ly/NaSX4X Follow us: @AirSpaceMag on Twitter Fucking obnoxious.

Turing_Machine 12y ago
"How is this even possible?" It doesn't seem at all implausible to me. Running a KC-135 and a crew of 4-8 to deliver the fuel at altitude isn't going to be cheap. JP-8 fuel appears to cost around $3.00/gallon at ground level, so a factor of 15 would be $45/gallon delivered. JP-8 has a density of about 0.8 kg/l, or about 6 lb/gallon. Civilian airline fares are somewhere in the neighborhood of $0.20/seat-mile. If you SWAG the weight of a passenger at 200 pounds, that's about $0.001/pound-mile. Now figure that the fuel might have to be flown 5,000 miles (possibly in multiple trips) That's $5.00/pound, times 6 pounds per gallon would give $30.00/gallon delivered (at commercial airline rates). Now figure that this is all military and $45/gallon actually starts to look pretty cheap. Edit: I think you edited your post. I assumed you were wondering how the cost could go up by a factor of 15. Now it looks like you're asking how this kind of mistake could happen. That's a different issue. :-)
nl 12y ago
How is this kind of oversight even possible? It's not. Ten years ago all the Airforce's money was going on the F22. If they'd asked for money for bomber engines then it would have been likely that it would have meant cut-backs in the numbers of fighters purchased. Remember, for the Airforce: Fighters always matter the most. Now the Airforce is looking at what to spend money on after the F35.
deleted 12y ago
[deleted]
mikeash 12y ago
I'm not sure it's true. It looks like there have been a lot of evaluations over the years. Here's one from 2003: http://www.acq.osd.mil/dsb/reports/ADA428790.pdf http://www.acq.osd.mil/dsb/reports/ADA428790.pdf A relevant quote from the executive summary: "A 2001 DSB study calculated the cost of fuel delivered in-flight to be $17.50 per gallon, using USAF provided figures, excluding the capital cost of tankers. Previous studies valued all fuel at about one dollar per gallon." While it looks like that oversight may have happened before, by 2003 they were looking at something like the real cost of tanker fuel. As for how that oversight is possible, this report discusses at lengths how evaluating the cost of tanker-delivered fuel is extremely difficult, because how much you use tankers depends a lot on exactly what kind of missions you fly, and a lot of the cost of tanker-delivered fuel is tied up in things like maintenance and operating overhead in the tanker fleet, so to save that 15x multiplier would involve reducing the tanker fleet as the B-52s needed it less, not just the simple act of burning less fuel. The report also mentions that only about 10% of the B-52's fuel was delivered in flight, so while it's expensive, it's not large in quantity. Put it all together and it's sensible to just do a conservative analysis where you assume fuel costs are the price at the pump. I'm not at all convinced that the relevant factor that changed the outcome of this recommendation was accounting for tanker costs. There are a ton of factors discussed, and it's a complex subject. One obvious factor can ben seen here: http://www.indexmundi.com/commodities/?commodity=jet-fuel&months=240 http://www.indexmundi.com/commodities/?commodity=jet-fuel&mo... Why did a 2003 study find that more efficient engines were worth the cost, while previous ones did not? I'm not sure exactly when the previous ones were done (this study just says there were three previous ones since 1996) but the fact that jet fuel suddenly got a lot more expensive right around the time this study was being done is certainly suggestive. In short, when a journalist says "they forgot" what it can actually mean is that in the analysis of a complex problem, a reasonable simplification was made.
username223 12y ago
> Also, this is the crap that got copied onto my clipboard when I tried to copy that quote: Tynt says "hi!" They are true pioneers in making the web a more hateful place.

Turing_Machine 12y ago

"How is this even possible?" It doesn't seem at all implausible to me. Running a KC-135 and a crew of 4-8 to deliver the fuel at altitude isn't going to be cheap. JP-8 fuel appears to cost around $3.00/gallon at ground level, so a factor of 15 would be $45/gallon delivered. JP-8 has a density of about 0.8 kg/l, or about 6 lb/gallon. Civilian airline fares are somewhere in the neighborhood of $0.20/seat-mile. If you SWAG the weight of a passenger at 200 pounds, that's about $0.001/pound-mile. Now figure that the fuel might have to be flown 5,000 miles (possibly in multiple trips) That's $5.00/pound, times 6 pounds per gallon would give $30.00/gallon delivered (at commercial airline rates). Now figure that this is all military and $45/gallon actually starts to look pretty cheap. Edit: I think you edited your post. I assumed you were wondering how the cost could go up by a factor of 15. Now it looks like you're asking how this kind of mistake could happen. That's a different issue. :-)

nl 12y ago

How is this kind of oversight even possible? It's not. Ten years ago all the Airforce's money was going on the F22. If they'd asked for money for bomber engines then it would have been likely that it would have meant cut-backs in the numbers of fighters purchased. Remember, for the Airforce: Fighters always matter the most. Now the Airforce is looking at what to spend money on after the F35.

deleted 12y ago

[deleted]

mikeash 12y ago

I'm not sure it's true. It looks like there have been a lot of evaluations over the years. Here's one from 2003: http://www.acq.osd.mil/dsb/reports/ADA428790.pdf http://www.acq.osd.mil/dsb/reports/ADA428790.pdf A relevant quote from the executive summary: "A 2001 DSB study calculated the cost of fuel delivered in-flight to be $17.50 per gallon, using USAF provided figures, excluding the capital cost of tankers. Previous studies valued all fuel at about one dollar per gallon." While it looks like that oversight may have happened before, by 2003 they were looking at something like the real cost of tanker fuel. As for how that oversight is possible, this report discusses at lengths how evaluating the cost of tanker-delivered fuel is extremely difficult, because how much you use tankers depends a lot on exactly what kind of missions you fly, and a lot of the cost of tanker-delivered fuel is tied up in things like maintenance and operating overhead in the tanker fleet, so to save that 15x multiplier would involve reducing the tanker fleet as the B-52s needed it less, not just the simple act of burning less fuel. The report also mentions that only about 10% of the B-52's fuel was delivered in flight, so while it's expensive, it's not large in quantity. Put it all together and it's sensible to just do a conservative analysis where you assume fuel costs are the price at the pump. I'm not at all convinced that the relevant factor that changed the outcome of this recommendation was accounting for tanker costs. There are a ton of factors discussed, and it's a complex subject. One obvious factor can ben seen here: http://www.indexmundi.com/commodities/?commodity=jet-fuel&months=240 http://www.indexmundi.com/commodities/?commodity=jet-fuel&mo... Why did a 2003 study find that more efficient engines were worth the cost, while previous ones did not? I'm not sure exactly when the previous ones were done (this study just says there were three previous ones since 1996) but the fact that jet fuel suddenly got a lot more expensive right around the time this study was being done is certainly suggestive. In short, when a journalist says "they forgot" what it can actually mean is that in the analysis of a complex problem, a reasonable simplification was made.

username223 12y ago

> Also, this is the crap that got copied onto my clipboard when I tried to copy that quote: Tynt says "hi!" They are true pioneers in making the web a more hateful place.