Re: MD-17 vs. MD-11F/DC-10F

Date:         Sat, 04 Jan 1997 03:30:39 GMT
Organization: Cargo Shipping Transportation Analysts
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In article <airliners.1997.4@ohare.Chicago.COM>, kls@ohare.Chicago.COM
>>> For many interesting cargo routes, however, it's range isn't enough more
>>> to eliminate fuel stops.  I think SFO-NRT was an example.  Both planes
>>> need a fuel stop, usually at ANC.  The fact that the -400F could fly a
>>> greater percentage of the flight before stopping is neither interesting
>>> nor useful.
>>Are you considering only transpac routes?  There are many others in the
>>world where the extra range of the 400F pays off very well.
>I said many routes, as that's what was said in the article I referred
>to (probably in AW&ST, though I still haven't found it).
>AW&ST lists cargo capacity of the 747-200F as 245,300 lbs, with the
>-400F only a little (9.4%) more at 268,300 lbs.  Their range numbers
>do not appear to be credible (4,080 miles for the -200F, 3,165 miles
>for the -400F) but that may be comparing max range for the -200F to
>full load range for the -400F.
>Here's what Boeing has to say about the 747-400F on
>   Weights and Ranges (carrying 124 tons of payload)
>   Max TO weight    Range
>   800,000 lbs      3,200 nm
>   833,000 lbs      3,760 nm
>   850,000 lbs      4,050 nm
>   875,000 lbs      4,450 nm
>Compared to the -200F, Boeing says
>   The -400 Freighter can carry 124 tons (113,000 kg) of cargo more than
>   4,400 nautical miles. An additional 26 tons of payload or 1,200 nautical
>   mile range is possible compared to Boeing's 747-200 Freighter.
>If I'm reading that correctly, it sounds like a -200F can carry 98
>tons 4,450 nm, or 124 tons 3,250 nm.
>SFO-NRT is 4,452 nm, beyond the range of either model.  Only by a very
>small margin for the highest MGTOW -400F, but ditching off the Golden
>Gate or in Tokyo Bay doesn't win any points.  :-)  Since both must make
>a fuel stop, the -400F's range advantage is of no consequence.  It can
>carry a higher payload, but the segment distance is such that the -200F
>payload is not substantially reduced by the need for a heavy fuel load.
I would like to add my 2 cents

1st both the 200 and 400F have the range ability to get to NRT
directly from SFO but the ACL (Aircraft Cargo Load) would have to be
reduced in order to add the additional fuel
In the example using 4452nm SFO/NRT :
The 747-200F would have to reduce payload to approx 95 tons inoder to
take on the additional fuel to make the safe trip to NRT
The 747-400F would have to reduce payload to approx 108 tons inorder
to take on the additional fuel needed to make the direct flight to NRT

But when you talk about MGTOW there are other conditions that come
into play. MLW ( Maximum Allowable Landing Weight) OEW (Operating
Empty Weight) ZFW (Zero Fuel Weight) The OEW becomes important
especially when dealing with passenger conversions to a freighter A/C.
Because some items can not be removed (ex Passenger Windows)
the OEW is higher than even the manufacturered 747-200F. An increased
OEW has a direct impact on ACL in many cases reducing the optimum
cargo  load weight to 95,000-100,000kg for carriage at 3200nm.
Weather conditions as you know also plays an important role in
reducing ACL.

 Aircrafts flying into ANC during the winter months many times have to
reduce ACL to stay within Field Limits (MLW) (MTOW)

Ironically the cargo mix today, (with the exception of Winter Months)
has aircraft volume out before weight out. Meaning that the internal
cubic capcity is full yet the weight capcity has not been reached. 

Therefore the increased Volume cpacity of 1 M/d POS and 2 Ld-3
positions must also be considered when comparing the 400F to the older

Note 747-200F is no longer manufacutured so only conversions of
passenger a/c and purchaces of used a/c remain however for new
aircraft the 400F is the best long range capcity aircraft arounf in my
humble opinion.

Robert Caton
Cargo Shipping Transportation Analysts