one discovers that the max. TOW is identical to that of the 772LR. The max. fule capacity is 47890 U.S. gallons, i.e. the "basic" figure of the 772LR.
Nevertheless, the range of the 777Freighter is 4,885 nautical miles, only, which is MUCH less than the max. range of the 772LR, 9380 nautical miles.
I assume that it is not the moderate difference in fuel capacity between the 772LR equipped with additional fuel tanks, 53515 U.S. gallons, and the capacity of the 777 Freighter, 47890 U.S. gallons, which could explain the large difference in the given figures for the maximum ranges of these airplanes (or is it?).
So, what is the reason why these planes, as similar as they seem to be to each other, have such a large difference in their max. range?
OldAeroGuy From United States of America, joined Dec 2004, 3141 posts, RR: 66 Reply 1, posted (3 years 5 months 2 weeks 2 days 1 hour ago) and read 2789 times:
Quoting Ferroviarius (Thread starter): Nevertheless, the range of the 777Freighter is 4,885 nautical miles, only, which is MUCH less than the max. range of the 772LR, 9380 nautical miles.
I assume that it is not the moderate difference in fuel capacity between the 772LR equipped with additional fuel tanks, 53515 U.S. gallons, and the capacity of the 777 Freighter, 47890 U.S. gallons, which could explain the large difference in the given figures for the maximum ranges of these airplanes (or is it?).
The primary difference in the quoted ranges between the 772LR and the 777F is that the 772LR range is for passengers only and the 777F range is for Max Structrual Payload (or Max Zero Fuel Weight, MZFW).
If you compare the ranges for both airplanes at MZFW, the range disparity will drop significantly.
In addition, the 777F has a higher MZFW than the 772LR, further reducing its range compared to the 772LR.
Using the page below as a reference, let's see how these numbers work out:
PhilSquares From , joined Dec 1969, posts, RR: Reply 3, posted (3 years 5 months 2 weeks 2 days 1 hour ago) and read 2776 times:
Quoting Ferroviarius (Thread starter): So, what is the reason why these planes, as similar as they seem to be to each other, have such a large difference in their max. range?
The 772LR has a MZFW of 461,000 Lbs while the 77F has a MZFW of 547,000. So in reality, what will happen is, assuming empty weights of what is presented (320,000 for the LR and 318,300 for the F) you will see the payload is much greater on the F, to the tune of 141,000lbs for the LR and 228,700 lbs for the F. So, assuming a F at MZFW and a LR at MZFW they can only upload 307,000 lbs for the LR and 221,800 lbs for the F.
Those weights are only approximations from the Boeing website. The LR will, in reality be heavier, but not to the point where it will negate the 80,000 lb fuel difference. What most freight operators want is the ability to maximize payload at a reasonable tradeoff of range. Passenger operators want to maximize range while being to carry a payload that will ensure a profit. Take a look at the MLW if you need any convincing of that. The F has a MLW of 575,000 lbs while the LR is at 492,000.
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