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-   -   Difference in range - 747-8I vs 747-8F (https://www.pprune.org/tech-log/626511-difference-range-747-8i-vs-747-8f.html)

shorthauler72 20th Oct 2019 16:41

Difference in range - 747-8I vs 747-8F
 
Dear Community,
I find the difference in range between the 747-8I (8,000 nm) and the 747-8F (4,120 nm as per Wikipedia) quite striking. Can anyone enlighten me of the technical and commercial reasons for this huge difference?

Best regards,
Shorthauler

Cough 20th Oct 2019 17:09

I bet the 747-8F is range with max payload, and 747-8I is range with a full customer load (probably no cargo). NB, payload on the freighter is massive compared with the pax version...

tdracer 20th Oct 2019 22:10

Cough has it right - the max fuel capacity (and hence range) is not much different between the -8F and the -8I. The Intercontinental has stab fuel that isn't used on the Freighter, but that's only a few hundred miles of range (whenever they turn a passenger 747-400 into a freighter, they remove the stab fuel system since it'll never be used). The difference in fuel burn per mile between the passenger and freighter at the same aircraft weight is pretty much insignificant.
The world cargo market is built around a system with leg lengths of less than 4,000 miles, and a 747-8F at max ZFW can carry over 150 tons of cargo using that system. For the most part cargo operators would rather carry more cargo and make a stop for gas somewhere rather than to make a long non-stop with a lesser cargo load.

B2N2 20th Oct 2019 23:42

Unless the customer requires minimum time in which case we fly at .86 :ok:

shorthauler72 21st Oct 2019 04:54

Thank you very much, very interesting.
Bestest,
Shorthauler

DaveReidUK 21st Oct 2019 06:35

https://cimg0.ibsrv.net/gimg/pprune....039a84c31b.jpg


https://cimg9.ibsrv.net/gimg/pprune....8a057f59f4.jpg

Note, as discussed above:

a) the slightly lower fuel capacity for the -8F (no stab fuel)
b) the 0.01 lower cruise Mach assumed for the freighter


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