My last post was about a shitty movie and in a few more before that, I wrote about the 737 MAX disaster.
That got me thinking about a very cheesy movie, that I happen to like called No Highway in the Sky.
Jimmy Stewart plays a nerdy and awkward engineer, what his British superiors call a “Boffin.”
What I love about this is that he’s a materials test engineer and failure analyst.
He is introduced in a lab where he is running a cyclic fatigue experiment.
The newest model aircraft for the company he works for is having crashes and he’s assigned to figure out why. He suspects metal fatigue and is sent to one of the crash sites, just to discover that he’s on one of these airplanes approaching the flight hours at which he suspects failure will occur.
Of course, the executives don’t want to believe him that their new, state of the art, plane is unsafe. He gets fires, just to be proven right in the end.
(Nudge, nudge, wink, wink, Boeing)
Some of the details are wrong. Fatigue isn’t that predictable, S-N curves are scaled logarithmically so cycles to failure at a given load can vary by +/- an order of magnitude. Also, fatigue is not that sensitive to temperature. There is thermal fatigue, which occurs due to cycles in thermal expansion. The fatigue properties in metals change with microstructure, so they are different above and below the ductile/brittle transition temperature or above the austenite transition temperature. But a difference of 40 degrees in aluminum isn’t going to change the fatigue life.
But I am willing to let that slide because this is the first and only movie I can think of where metal fatigue is the villain.
What’s more interesting is that this movie was released in 1951, and the de Havilland Comet was launched in 1952, and that is perhaps the most famous case of fatigue failure in commercial aircraft.
A de Havilland disaster movie – a la Sully (the 2016 film) – would be interesting. There were a number of courts of inquiry that ultimately lead to fatigue being identified as the cause of hull losses. Early crashes were blamed on pilot error which was actually a stall problem, which was turned into a different air disaster movie called Cone of Silence which was released in the US as Trouble in the Sky.
Despite the cheesiness and factual inaccuracies, I love this movie because a metallurgist is the hero.
It’s also what I used to do for a living, and would like to do again: failure analyst and materials test engineer. This is related to an aviation job that I wouldn’t mind having called a damage tolerance engineer.
Materials test engineer: “What does it take to break it? Let me find out by breaking it on purpose.”
Failure analyst: “Why did it break?”
Damage tolerance engineer: “How broken can it be before it totally comes apart and kills people?”
The general metallurgical principles are the same. It’s something that I enjoy doing and happen to be really fucking good at.
The movie is available online, so if you are at all nerdy and technically inclined.
Also, if you know about a need for a failure analyst (full time or consultant) let me know in the comments, it would be appreciated.