Re: A3XX vs B747-600 (was: Airbus lawsuit coming?)

From: (C. Marin Faure)
Organization: Northwest Nexus Inc.
Date:         07 Sep 96 17:09:02 
References:   1 2 3 4 5 6 7 8 9 10
Followups:    1
Next article
View raw article
  or MIME structure

In article <airliners.1996.1716@ohare.Chicago.COM>, wrote:

> So, my qestion is: is it really that simple to modify an existing wing?

No.  Engine mounts, flap assemblies, landing gear systems, all have to
modified as well.

>is it really that expensive to design a new wing ?


>is the difference between the 2 really that big now that computers and
previous designs help ?

Yes.  I assume you mean is the difference between a redesigned wing and an
all-new wing that big.  A redesigned wing is going to be a compromise to
some degree.  The only reason there are winglets on the 747-400 wing, for
example, is to help that ancient 1960s airfoil go farther by reducing the
drag somewhat.  The winglets and the wing extensions they're attached to
was a relatively economical way to get more range out of the airplane
without going to the expense of designing an all-new wing.

If customer demand is sufficient to warrant building new versions of the
747, it will have an all-new wing design based on the state-of-the-art
wing technology we put into the 777 wing.  The industry has learned a lot
about wings, wing structure, and aerodynamics since the Boeing 737 and 747
were designed, so much so that the performance improvements of today's
wings are considerable.  That's why the 737 family is getting a new wing,
and why the 747 family will get a new wing if the program is launched.
The performance improvements achieved by today's wing technology now makes
the cost of an all-new wing design worth the money.

>From an aerodynamic standpoint, all the fuselage does is keep the wind out
of the passengers' and flight crews' faces (the finance directors at the
airlines claim that the fuselage does a little more than that, of
course).  If you already have a good fuselage, with a cross section and a
seating arrangement that satisfies the market demands, why change it?
It's just a tube.  So putting a new wing, new powerplants, and new systems
in an existing fuselage is, in effect, creating a brand new airplane.
Your fuselage design just happens to be done already.

C. Marin Faure
   author, Flying a Floatplane