A380: Repeating the 747's history?

I'm somewhat surprised to see Airbus having such difficulties
considering the A380's having been designed on a computer (3D digital
mock up). I thought the main benefit of CAD was to have the ability to
test for systems integration before any metal is cut(?) Of course this
is an extremely complex aircraft with many complicated systems that
must all play together, and the latest wiring harness issue may not be
related to any design deficiency.
By comparison, I recall seeing a documentary on the 747's service entry
(1970) that had its share of gremlins. (IIRC a big source of headaches
were the Pratt JT9D fans) The documentary didn't go into much detail
about the program's problems, (I'm sure there were a few) but that
airplane was designed by engineers on drafting tables and not
computers. I just assumed new aircraft designs would have smoother &
shorter development because of modern computing power.

In article . com,
"Kingfish" wrote:

I'm somewhat surprised to see Airbus having such difficulties
considering the A380's having been designed on a computer (3D digital
mock up). I thought the main benefit of CAD was to have the ability to
test for systems integration before any metal is cut(?) Of course this
is an extremely complex aircraft with many complicated systems that
must all play together, and the latest wiring harness issue may not be
related to any design deficiency.
By comparison, I recall seeing a documentary on the 747's service entry
(1970) that had its share of gremlins. (IIRC a big source of headaches
were the Pratt JT9D fans) The documentary didn't go into much detail
about the program's problems, (I'm sure there were a few) but that
airplane was designed by engineers on drafting tables and not
computers. I just assumed new aircraft designs would have smoother &
shorter development because of modern computing power.

Physical mockups were actually constructed at that time of various
components. If it didn't fit, you saw why.

Kingfish writes:

I just assumed new aircraft designs would have smoother &
shorter development because of modern computing power.

I think what actually happens is that designs take the same amount of
time as before, but the resulting aircraft is fifty times more
complicated.

--
Transpose mxsmanic and gmail to reach me by e-mail.

I just read an article indicating that the various countries involved used
non-compatible software, each thinking that theirs was the best, and they
were wrong.

Bob Gardner

"Kingfish" wrote in message
ups.com...
I'm somewhat surprised to see Airbus having such difficulties
considering the A380's having been designed on a computer (3D digital
mock up). I thought the main benefit of CAD was to have the ability to
test for systems integration before any metal is cut(?) Of course this
is an extremely complex aircraft with many complicated systems that
must all play together, and the latest wiring harness issue may not be
related to any design deficiency.
By comparison, I recall seeing a documentary on the 747's service entry
(1970) that had its share of gremlins. (IIRC a big source of headaches
were the Pratt JT9D fans) The documentary didn't go into much detail
about the program's problems, (I'm sure there were a few) but that
airplane was designed by engineers on drafting tables and not
computers. I just assumed new aircraft designs would have smoother &
shorter development because of modern computing power.

In article ,
"Bob Gardner" wrote:

I just read an article indicating that the various countries involved used
non-compatible software, each thinking that theirs was the best, and they
were wrong.

why, that's hard to believe :-)

--
Bob Noel
Looking for a sig the
lawyers will hate

john smith wrote:
Physical mockups were actually constructed at that time of various
components. If it didn't fit, you saw why.

Correct, but the CATIA program used in the A380 development allowed the
designers to virtually mock up the components and check for
interference etc. The same program was used during the 777 program
development, apparently with better results(?)

Bob Gardner wrote:
I just read an article indicating that the various countries involved used
non-compatible software, each thinking that theirs was the best, and they
were wrong.

Sounds like a failure of the Project Management Office (PMO). And don't
forget the fact that three delays were announced in the span of about a
year.

Bad PMOs have a habit of creating a slippery slope of cutting corners
coupled with a reluctance to bring up issues for fear of your boss
getting fired.

Will be interesting to watch. I'd hate to be the one to get version one
of the plane.

Marco

"Kingfish" wrote in message
ups.com...
I'm somewhat surprised to see Airbus having such difficulties
considering the A380's having been designed on a computer (3D digital
mock up). I thought the main benefit of CAD was to have the ability to
test for systems integration before any metal is cut(?) Of course this
is an extremely complex aircraft with many complicated systems that
must all play together, and the latest wiring harness issue may not be
related to any design deficiency.
By comparison, I recall seeing a documentary on the 747's service entry
(1970) that had its share of gremlins. (IIRC a big source of headaches
were the Pratt JT9D fans) The documentary didn't go into much detail
about the program's problems, (I'm sure there were a few) but that
airplane was designed by engineers on drafting tables and not
computers. I just assumed new aircraft designs would have smoother &
shorter development because of modern computing power.

As someone who is involved in the design of industrial equipment and
facilities, I submit that "computerization" - i.e. CADD and other time
saving tools have made it so easy to make design changes that designs are
seemingly *never* frozen. This means that all of the involved parties don't
get the opportunity to make sure their pieces actually fit the product at
its frozen stage. Beyond that, airplanes have closer tolerances and less
margin to move things around than many other items, meaning that making "my"
new assembly fit "your" new component can be extremely difficult. And may
involve the modification of several other components or systems via the
ripple effect.

On top of those issues, the complexity of aircraft systems has increased
several fold over the years. Integrating those systems is a far bigger task
than building a flyable airframe.

CAD programs like CATIA work great at making everything fit mechanically.
It sounds like a lot of the 380 delays are related to wiring issues due to
the large number of customizations for the individual airline customers. I
suspect that CATIA doesn't help solve that problem very much.

Mike Schumann

"Kingfish" wrote in message
oups.com...

john smith wrote:
Physical mockups were actually constructed at that time of various
components. If it didn't fit, you saw why.

Correct, but the CATIA program used in the A380 development allowed the
designers to virtually mock up the components and check for
interference etc. The same program was used during the 777 program
development, apparently with better results(?)

Today's WSJ (Thursday) reports that Airbus has announced the first
delivery of an A380 will not occur until October 2007, with service
beginning first quarter of 2008.