The Wall Street Journal Saturday ran a fabulous piece on the DC-3 airplane, an estimated 500 of which are still flying. Tens of thousands were made, 3,000 during the war effort in the Soviet Union. What struck my eye was the wing testing when the plane was designed. According to an interview in 1985 with chief designer Arthur Emmons Raymond to celebrate the plane’s 50th birthday, bulldozers were run over the wings to test their strength. When was the last time you heard about stress testing like that? A cursory check of the web revealed no DC-3 ever crashed from structural failure. I wonder if I should suggest bulldozers to the 787 stress test folks at Boeing. Famous for their relative size and strength, the DC-3 could glide back to earth even when it was under half power or without it entirely. Here’s one recent account of a crash after an engine failed. All walked away without serious injury.
The legendary Raymond died at 99 in 1999 and his obituary reads like a veritable (and brief) history of commercial aviation in its formative years. PBS aired an episode on the venerable plane in a series on commercial aviation called “Chasing the Sun” a few years ago. The DC-3 more than any other plane ushered in the era of commercial air travel.
The choice between helical and spur gears in gearboxes may seem straightforward. But with planetary gearboxes, however, the choice between helical and spur gears requires some additional thought. Here’s what you need to know to make the right choice.
Cas Smith is a biological engineer at Terrapin Bright Green, a consulting firm that specializes in green and sustainable design. At the core of his work is to explore how biomimicry can inform sustainable design. He discussed biomimicry and its implications for design and solving some of the world’s sustainability issues in an interview with Design News.
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