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Comment by bunabhucan | Hacker News Reader

I remember an engineer telling me the physical drawings for the 747 weighed ten times as much as the plane itself.

1000 sheets of paper weighs 10 lbs, the 747 weighs 910,000 lbs, so there were 91 million sheets of paper describing the 747? Does not seem accurate

The 747 has around 6 million individual parts, 15 sheets of paper per part doesn't seem unreasonable.

Just detailed schematics of a given plastic knob in the cockpit should take at least a few pages, nevermind something more complex or critical like turbine blades.

The 6 million figure includes fasteners. Half of the parts of fasteners and there are only 75k engineering drawings. Engineering drawings rarely run more than a few pages per part.

https://www.boeing-747.com/fun_facts_from_boeing.php

Construction drawings are not done on A4. Typical drafted drawing is uses handful of ft by ft range, say 3x4. So that should give ~2 orders of mag less sheets. Does 10,000 sheets of drafting paper sound more reasonable?

Internet says 747 has 6,000,000 parts, half of which are fasteners. So 3m individual components. “171 miles” of wiring. Blah blah. I can easily see 10k drawings to cover that beast, soup to nuts.

3x4 is about right, but the original 747 drawings were not drawn on paper, they were inked on thick thermal and humidity stable mylar. Some detail parts may have been defined multiple (up to a half dozen) E sized (36”x48”) mylars. Then there were separate drawings for each assembly of detail parts. Then there was all the manufacturing planning and detailed work instructions to fabricate each level of assembly. Then there is all the documentation associated with lab qualification testing prior to flight. I have personally authorized qual test reports in excess of 3000 pages, where ~100 pages was my content and the rest was all backup data.

If you adjust the size of the paper, it can be true no matter how many or few parts there are.

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