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3D CAD and the 757 | |
I read this article
stating that the 757 that was discontinued in 2004 is still in use. Why?
"There's no denying the 757 is an old plane
that was designed in the late 1970s, but the versatility of the plane is
remarkable and unmatched," Smith, the author
of the book Cockpit Confidential, told Business Insider in
an interview. “It’s profitable on both short-haul domestic as well
as trans-Atlantic routes." The KC-135, 707, 727, 737 and the 757 all have the
same basic airframe. Today Boeing sells thousands of 737s. This airframe
design is over 60 years old and is still viable. And as you see above
many airlines are even updating their existing fleet of 757s. I thought, how would they bring this airplane back
in production? Do they even have draftsmen to modify the drawings? How would they mix CAD and manual drawings? You know I don’t think they could technically or cost effectively do it!! Here is another article suggesting that Boeing bring back the 767. An NMA alternate: Boeing’s potential 767-X(NMA - New Midsize Airplane) You just have to look at the KC-46 tanker to see if this is a problem.
Of course, the 757 was
not designed in 3D CAD or any CAD. The first airplane designed in 3D CAD
Catia 3/4 was the 777. But the engineering deliverable was still the
drawing and delivered as a print. Yes, they did also deliver the model in
IGES format to the suppliers. IGES was a good format since it was
made up of 3D wireframe and surfaces. They were very dependable and rarely corrupt. Boeing 3D CAD History 747 started 1964, introduction 1970, No CAD
(Pre-design for C5 project should be considered) 767 started 1976, introduction 1982 No CAD, Manual
drawings only.
777 started 1988, introduction 1995 All 3D CAD with drawings and 3D model This was going to be an electronic airplane. Yes,
they still generated drawings from the 3D model and were delivered as prints.
Boeing draftsman at the time called them the “Flat file”. One funny
thing about the process was that engineering management said there would
be no mockup made, it would be an electronic model. A mockup was a
full-scale model of the airplane for verification of the assembly and
used for design considerations. Nope, they didn’t have "one" mockup,
but they
had dozens of full sized model verifications. It just makes you chuckle. We have to note here, the Catia 4 to 5 fiasco. Dassault released a 3D CAD program with the same name as the previous version yet it was a totally different program that was not compatible. This was a costly transition for both Boeing and Airbus. It was shocking that huge aircraft companies could be so short sighted.787 started 2003, Introduction 2011 ALL CAD no drawings only the 3D model. Yes, the 787 had other problems with the
introduction of new revolutionary processes. But it will never be
profitable, the advantages are not worth the true cost of the airplane. After reading the above facts, you have to ask
this question! Why in the world when 3D CAD was added it took
longer to design an airplane. Shouldn’t it be significantly shorter?? Boeing now has a 3D CAD
system that cost millions and millions of dollars, it is a complex design
systems that can take a year to just get proficient, forcing Boeing and other
companies to demand the engineer have Catia 5 experience. Thousands of
new Infotech employees to maintain the systems. A high level of
incompatibility with the suppliers and much more. With the 787, Dassault added PLM with the Catia 5. Boeing got rid of the Drafting Group and Document Control with the promise that this new wonderful 3D CAD and PLM system could managed the complete engineering department. Highly experienced draftsman started disappearing without any provisions to get the engineers educated to fill the knowledge vacuum created. 3D CAD was now the tool of the new 3D CAD engineer. The engineer went from managing draftsman to being managed on the daily form, fit and function grunt design work. They were now required to create all the engineering documentation, check it, review it, release it and maintain it. I love to see the degreed engineer brag about their 3D CAD prowess, not even realizing how far they have fallen. Educating the New 3D CAD Engineer - 2015 Catia 5 is nothing more than a poorly designed Pro/e (Creo) clone with the same dated separate part, assembly and drawing format. The PLM folks soon realized that the associated drawing was not easy to maintain. They started looking for solutions. They came up with MBE (Model Based Enterprise).
This is an interesting aside. Instead of the PLM folks looking to a more document management friendly 3D CAD system. Let's say one that had a single model environment and integrated drawings. They attempted to build a system based on the dated and convoluted Pro/e (Creo) clone with the separate parts, assembly and drawing. Their failure to effectively do this made them come up with the bizarre MBE and other solutions that companies like Boeing and Airbus are suffering under today. The solution was to create a new 3D drawing format
called the PMI (Product Manufacturing Information). These native 3D
models with 3D annotation were now the design authority. Change went
from an inexpensive added ADCN (Advanced Drawing Change Notice) attached
to the
drawing to having to directly revise the model and rerelease. You just
have to laugh at the extra time and exposure to Murphy this costly
process now allows.
This all was done by those that had no applicable
knowledge of the engineering process. Sadly, they are still in charge
convincing everyone (no draftsman left) that this highly inefficient
system is the new normal. "I feel I have proven that the past
system, when the
engineering was based on the drawing, was a much more productive system.
Draftsman did virtually all the work with high levels of experience.
When I worked at Boeing 747 flight deck the lead draftsman was the go to
guy. He was brilliant in his knowledge. Problems were solved with ease."
So, when you say “Oh that guy is old fashion” when he brings up going back to complete drawings from the 3D model, think again. You cannot short cut engineering. Every small mistake in engineering costs 10-fold down the line with incorrect parts and slipped schedules. It is quite odd that management is so inept they cannot even connect the dots. There is just no one with the necessary applicable knowledge in the industry to expose the vested interests that keeps this ineffective and costly system in place.
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