Re: B777-300/B777-300ER???

Date:         13 Jan 99 02:13:33 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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>the suffix "IGW" seems to be used inofficially (by airlines and possibly
>also by Boeing) ...

Given that it's used by Boeing in press releases, on their web site (see
http://www.boeing.com/commercial/777-200/product.html), and various
other places, I'd say it's pretty official, though recently they did say
thay were changing the 777-200(IGW) model designation to 777-200(ER).

>Note that IGW does not necessarily mean that there is more fuel capacity
>nor that the maximal range is augmented over the base model.

Perhaps not in general terms, but the only aircraft currently in
production for which Boeing has used the designation is the 777-200(IGW)
and one of its distinguishing features, relative to the base model of
the 777-200, is an added center fuel tank.  The wings and landing gear
also have structural reinforcements, and some portions of the wing skin
may be of heavier gauge.  The higher fuel capacity and gross weight
imply greater maximum range.

>Higher
>weights can just mean that you get a more favourable trade off between
>payload restrictions applying and fuel quantity required when you're
>flying on route segments approaching the range/payload limits of the
>aircraft.

True, though the primary reason for the IGW's existence is greater
range.

>And also remember that it certifying existing types to higher weights is
>not a new story at all. The MTOW for B747-200Fs and for B747-400Fs (just
>as an example) could be raised some way down the production process.

In many cases you can even upgrade an older aircraft to the newer MGTOW.
But not always, and you can't (usually) upgrade one model to another.
You can buy a 777-200 with a 506,000 lbs MGTOW and subsequently upgrade
it to as high as 545,000 lbs, but you can't turn it into a 777-200(IGW),
just as you can't upgrade a 747-100 into a 747-200B.

Boeing still offers both models of the 777-200 because there is a
(limited) market for the less capable non-IGW model.  Not a very big
market, perhaps, but United ordered a few more for domestic use last
year.  That's the only non-IGW order I'm aware of since the IGW became
available, but once the Asian financial crises eases there could be
orders from that region for regional routes where the 777-300 is too
large.

--
Karl Swartz	|Home	kls@chicago.com		http://www.chicago.com/~kls/
		|Work	kls@netapp.com		http://www.netapp.com/
"The average dog is a nicer person than the average person."
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