Ford Tri-motor factory -- Worlds first all-metal airliners

[PCGAMEfreak]

Not only corrugating is great for stiffness, but also strength. If you look at a cardboard box, you will see that same exact design, and that's where it gets it strength from.

[XOBubba]

Neat airplane and a great piece of history! Note OSHA wasn't around then! I'd love to get a ride in the EAA's craft. Thanks for sharing these!

[Knoss]

What OSHA would have a problem with worker not wearing a respirator wile spray painting parts with lead based paint.