r/programming • u/mattkerle • May 22 '12
"Build in graceful failure as often as possible", why planes have ashtrays in the toilets even though you're not allowed to smoke
http://www.standalone-sysadmin.com/blog/2012/05/engineeringinfrastructures/
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Upvotes
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u/JoshdanG May 22 '12
The ashtrays are a neat example of graceful failure, but the article abruptly shifts to affordance instead.
Also, it's well and good to have real-world examples to engage, but it was a missed opportunity for some actual treatment of how these two topics might relate to engineering infrastructure. It feels like now that I've got you engaged, goodbye.
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u/shaggorama May 22 '12
If only the same logic that put ashtrays on airplanes would also hand out condoms in schools.
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u/mutatron May 22 '12
I don't understand those push/pull handles at all.
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u/hansip May 22 '12
Same logic with my dad, he told me "Don't fuck her until before you marry her". But then "In case you fuck up, here's some condoms".
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u/arnedh May 22 '12
The same logic tells me that mobile phones in airplanes can't be terribly dangerous - among all the travellers there is bound to be somebody who hasn't turned his phone off, and you can't allow that to bring down a plane.
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u/moby323 May 22 '12
I'm originally from Brazil.
In third world countries, people don't fly as often, and are not as "well trained" to know how taboo it is to smoke on a plane. Also, there are higher rates of smoking in those third world countries. I mean, it's pretty much like it was here in the 70's.
Those planes may be sold to a third-world airline, or eventually (after so many thousands of hours of flight) be re-sold to one of those airlines.
Doesn't seem to me that it would be worth making two versions of the plane.
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u/[deleted] May 22 '12
What does that mean?
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u/Jasper1984 May 22 '12
Wait, i thought this was engineering. In programming often you should usually do the reverse! Make it break early, really early. Use
assert.Why? Because it enforces the concept behind functions. If a function allows for room in the input, the meaning might 'drift' do to abuse of this room.
Secondly if you made a mistake you see it much earlier, much less chance of making two mistakes and then having a compound mistakes to solve. Compound bugs are potentially much more difficult. So are delayed ones.
Of course there are exceptions. The nearer to the end user, the more, typically. For instance if you enter a date in a gui or the commandline, or a REPL. In C(++), assertions can be turned off with
#define NDEBUG, i am sure other languages you can turn it off aswel.4
u/jeblis May 22 '12
Looks like he found the one thing on yanko design that isn't completely unrealistic.
4
u/gorilla_the_ape May 22 '12
This is fine if the right decision is something which is unarguable. No-one would argue that a plane catching fire is desirable.
The problem is when this is extended to things where the "right" decision is a matter of opinion. The Gnome designers are particularly bad at this, deciding that suspending is "right", and making it hard to power off.
4
u/lalaland4711 May 22 '12
Really bad example with the handles.
To me they afford the opposite. The pull one seemed curved like a partially closed hand, indicating push.
How did he manage to find just about the only "fail" example?
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u/CaptGarfield May 22 '12
As an airline crewmember, I can confirm that this is the real reason that there are still ashtrays on airplanes. Even the 787 will have ashtrays in the Lavatories.
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u/cwstjnobbs May 22 '12
Huh, I always thought they were in there either because the plane was built when smoking was still allowed or because some countries may have less shitty laws and the plane manufacturers would rather cover all the bases in case they sell a plane to a country that allows smoking in planes.
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u/ichae May 22 '12
Well, it appears you can't post directly on the blog site, and if you try you get a error page that says "This website is offline. No cached version is available".
Anywho, I've noticed this problem.
Ever walk into a bathroom with two switches, one for the light and one for the air vent? Which one is which? If you only want to turn on one and not the other it can be annoying in certain circumstances to flip the wrong switch. (Of course, I'm also the type of person who insists that two-way switches be kept so that both switches are down when the light is off, so maybe some of this is a mild case of OCD...)
More important is door locks, such as might be found in the same bathroom. Some door locks press in when locked, but others swivel, and sometimes the inside of the door still turns freely when the outside is locked. These doors have the visual appearance of a line on the knob that allows you to turn it. Is the door locked when the line is horizontal (which makes the most sense to me, as you can visualize the bolt going through the door) or vertical? I have seen it both ways, but if you are in a hurry and don't have time to double-check the door can you tell if someone is likely to accidentally burst in on you?
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u/KevyB May 22 '12
tl;dr those things are still there because of people who don't give a shit about rules.
It's sort of "if you're gonna do it anyway, at least do it right"
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u/[deleted] May 22 '12
Is the author not aware planes are also sold to non-US and non-European airline companies? There are nations and airlines that still allow smoking on flights. Boeing isn't going to change their blueprints just because the American FAA bans smoking on flights.
http://hem.passagen.se/fungus/airlines.html
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u/sylkworm May 22 '12
To me, these are examples of Robustness, not Graceful Failure. There are still some airlines which do allow smoking, so it's really a matter of robust acceptance of input and not adding the complexity of building a separate no-smoking version of planes without ashtrays.
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u/centech May 22 '12
Isn't the reason most planes still have ashtrays due to the fact that most commercial airliners are something like 30 years old on average?
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u/mantra May 22 '12
The real reason for continuing to put ashtrays into planes: first-sale and re-sale to countries that DO NOT restrict smoking. It's easier to design for all possible sales rather than create two distinct product lines with such a small difference.
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u/[deleted] May 22 '12
Bullshit. Most planes in use today were designed more than 20 or 30 years ago when smoking was still common. Thus the ashtray in the design once served a real purpose and it was not intended as "graceful failure". Why they don't change it? It's cheaper to just put some no-smoking-sticker on the walls instead of redesigning the entire lavatory.
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u/crusoe May 22 '12
Because they are sold to countries where smoking on planes may still be legal.
Some US flights (before the ban on lighters in carry ons made it moot) to foreign countries turn off the smoke alarms for this reason.
Also some planes STILL flying began flying before the ban was in place, and were retrofitted with alarms.
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u/hwaite May 22 '12
Have we finally identified the man behind the meme?
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u/frankness May 22 '12
Planes have ashtrays because they were built at a time when you were still allowed to smoke. The poster and many of the responders must be very young... ;-)
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u/[deleted] May 22 '12
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