Re: Why a new super-jumbo isn't going to be built anytime soon.

Date:         23 Apr 97 02:58:16 
From:         tassio@watson.ibm.com
Organization: IBM T.J. Watson Research Center
References:   1 2 3
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Terry Schell wrote:
>(...)Furthermore, we could get a 100 fold
>increase in air travel if everyone flew as much as Americans currently
>do (even without an increase in population).
>In short, I don't think you "lack-of-demand-growth" argument
>holds much weight. There may well be reasons why a super-jumbo does
>not get built for a while... but it won't be because of a lack of
>demand for passenger miles.

At first when I read this I thought sure, my argument is nonsense.
But the 100-fold figure seemed awfully high to me. So I pulled up
Boeing's data on rpms per region and region pair for 1995.
Within North America there were 423 billion rpm (brpm) flown.
There were also 362 brpm flown between North America and other
regions of the world. As I'm looking for rpm per capita, I'll assume
50% of those 362 rpms were flown by North Americans. Total is 604brpm.
Assuming North American population as 290million, each person
flew an average of 2083mi.

"If everyone flew as much as Americans" (ok, I'm lumping the
Canadians in), for a world population of 5.2bil, I'd get 10830brpm.
Back to the Boeing data, the world flew 1601brpm. So, the increase
ratio would be 6.8 (not 100), for everyone to fly as much.
My computation has a series of unmentioned assumptions, but roughly,
this number should be between 6 and 8.

I'm sure there are more interesting numbers that could come out
of this data. I tried the same computation on Boeing's projections
20 years from now and the ratio seemed just a small bit lower.
I thought it can be an indication that Boeing is both overestimating
growth in North America and underestimating growth in the rest
of the world.

Now imagine the world does catch up. A seven-fold growth in the
world coming just from outside North America would translate into
a 10-fold increase in other parts of the world. Would there be a lot
more (i.e., _10_ times) flying between say London-Johannesburg,
London-Singapore, London-HongKong, London-Tokyo,
Tokyo-Singapore, BuenosAires-Madrid or HongKong-Sydney?
Of course not, because traffic would spread more homogeneously.
There would be a lot of flying between Dhaka-AddisAbaba,
Beijing-Sydney, Luanda-RioDeJaneiro, Nairobi-Singapore,
Paris-Jakarta, Kinshasa-Calcutta, Istambul-Denpasar.

I still concede that air traffic can grow many-fold even if
the world population stopped growing today. But if traffic triples
in the next 20 years, larger airplanes won't necessarily be
required. I hadn't originally said that, but only that "the size of
the largest airplane will converge to a given number". Could be
3000, 5000, but I think that number is a helluva lot closer to 420.
Tassio