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Why airplane bathrooms have ashtrays (standalone-sysadmin.com)
475 points by MPSimmons on May 22, 2012 | hide | past | web | favorite | 143 comments

The illustration of the door handle is a great example of piss-poor affordance. A slight ridge is not going to clearly communicate push vs. pull. Especially since our fingers, when gripping, actually like a ridge to fill in the open angle behind the first knuckles.

If you want someone to push, give them a big fat flat metal plate or bar to push on. If they can't pull, they are guaranteed to get it right every time. I bet pretty much every restaurant kitchen and high school gym door in the U.S. gets this right.

The door handle could actually be described as an anti-affordance. I looked at the photo and thought to myself what a great idea it was that it gave you a comfortable ridge for your knuckles while pulling and a nice rounded bit (instead of a sharp-edged flat surface) to push on.

That is, it signalled to me the exact opposite of the designer's intended use. I would have been doubly surprised if pulling on that clearly "pull-only" handle didn't open the door.

Why not have a handle that's either concave or convex, bowing in or out, to indicate the desired direction? If it's shaped like a hook, you'll pull on it, or more like a dish, push on it.

Me too. Did the blogger just label it wrongly?

I would have tried to rotate both of those handles. You want to know a great user interface that is universally understood?

PUSH: http://www.vanseodesign.com/blog/wp-content/uploads/2010/08/...

PULL: http://www.artfactory.com/images/Door-Handle-HH199.jpg

The door handle sacrifices usability for aesthetics.

Except your pull handle looks like it is on both sides, and the big flat surface regardless of the shape of the handle communicates "push" to me.

PUSH looks perfect to me, but while I wouldn't say the PULL example is anti-affordance it is at best confusing. If the handles were rounded and rotated so the curve faced the user (http://image.made-in-china.com/2f0j00fviQTDboYJqL/Door-Pull-... OR http://www.bnl.com.au/catalogue/door_handles/6x4%20handles/D...) then I'd agree 100%.

This is an important lesson. Programmers are constantly blaming users for this and that. Yes, it can make sense for stuff that's rare, but building your apps around the idea that users are rational human beings who read error messages and instructions makes no more sense than building your apps around the idea that computers have unlimited processing power and storage space.

99% of the time, "that was the user's fault" just doesn't cut it. You need to be design around the user's flaws just as you need to design around the computer's flaws, the network's flaws, the OS's flaws....

That's interesting news to me. I did wonder why smoking paraphernalia continued to appear in planes that were covered in anti-smoking insignia. I always assumed that the bathrooms, seat etc were made in large quantities, and that there are a lot of countries in the world where you can still light up in a flight, not to mention privately owned planes.

I once flew on a Japan Air Lines flight back in the '90s. At that stage they still had the back 6 rows or something as smoking seats. The girl who assigned my seat at check in didn't realise this and allocated me there. I just sat there and took it for 8 hours - nowadays I would have loudly demanded an upgrade out of there - but I was somewhat meek in accepting my fate. The lady next to me had just been to bury a relative in a car crash and was on the way back home. She must have drank half a bottle of whisky and smoked two packets of cigarettes. When I arrived I smelt like a tobacco spitoon and felt as though I had sand rubbed in my eyes.

Allowing smoking on planes was and is a terrible idea. The fire risk alone should immediately discount it.

"The fire risk alone should immediately discount it."

A quick Google turns up only two airline accidents possibly attributed to cigarettes (a 1982 Illyshin IL-18 crash in Guangzhou, China and a 1973 crash in France). Pretty minimal, given that smoking was allowed on millions of flights for close to 90 years.

We fly a lot more now than before deregulation, while many countries are just emerging with people who commonly commute via planes. I wouldn't be surprised if passenger miles from 1990 to 2010 were larger than 1900 to 1990. Flying used to be a high-class affair, now anyone can fly; not allowing smoking is probably a good thing in that context.

At least, here in China, people are not careful in the way they smoke, and I wouldn't get on a plane that allowed smoking. Ever see a Starbucks trashcan go up in smoke after someone was told they couldn't smoke there? Its quite funny the first couple of times, but it gets old after that.

That's two more crashes than is necessary if you ask me. You're not allowed to take firecrackers on a plane, and there probably isn't any recorded crashes from firecrackers.

Besides, you don't need to crash a plane to make it a bad idea. Just damaging it or creating a smoke filled (as in burning material, not cigarettes) interior is bad enough.

I can see how you might think it's OK if you're a smoker, but I'm happy that there isn't any smoking.

The fire risk alone should immediately discount it.

In case you haven't noticed, the trash bins on airliners are designed to be air-tight so that a discarded cigarette that ignites a trash fire does not burn for long. There is essentially no fire risk, as a small fire will be immediately extinguished by one of the other 200 people on your plane with nothing else to do. Cigarettes are dangerous if you are smoking alone and fall asleep in bed. When 200 other people are within 50 feet of you, not so much.

A cancer risk, however, definitely yes.

> Allowing smoking on planes was and is a terrible idea. The fire risk alone should immediately discount it.

Yet, people still smoke around pumps at gas stations and even throw the butt to the ground.

And given that a lit cigarette is not hot enough to ignite gasoline vapor what is the issue?

Representative sample: http://www.guardian.co.uk/uk/2007/feb/27/smoking.film

From the article itself, gasoline ignites at 270°C and cigarettes burn at 700°C+. "we tried a bunch of stuff and it did not do squat" is not quite scientific enough to have me stand in the middle of a gas puddle while a dumbass throws a butt at my feet. I bet you would not take the risk either.

The real danger is the unlit cigarette.

This reminds me of a presentation by Twitter at a conference where they discussed MTBR (Mean Time Before Recovery) instead of MTBF (Mean Time Before Failure). Instead of trying to prevent all possible failures, they focused on acceptable failure and speedy recovery. If a server takes twice as long to response to a request, mark it offline and let the automated recovery process diagnose the problem and if it's just an anomaly mark it back online.

It was pretty interesting and we took a good look at our architecture and found ways to better cater to acceptable failures.

Audi's strategy in the early 2000s for winning Le Mans 12- and 24-hour endurance races against Bentley was to engineer their cars around failure. The Bentley cars were faster, but Audi engineered theirs to be easier to fix. Over such long races, there were bound to be crashes or failures of various parts and the faster Audi could fix their cars, the quicker they could get back out on the track to outlast the faster cars.

A great example of this was that Bentley used the lightest bolt they could everywhere on the car to minimize weight, but Audi used the same size bolt everywhere to minimize the number of tool changes needed to replace the parts.

Airliners are designed to withstand failure, not to not have any failures. It's a change in perspective, and is very effective.

Both the Fukishima plant and the Deep Water Horizon rig were unable to withstand single failures.

> the Fukishima plant ... were unable to withstand single failures.

I don't know the details, but I'm pretty sure you can't put the blame of the Fukushima disaster on a single failure.


- structure withstood magnitude 9 when designed for at least magnitude 8

- following the shock, rods went down successfully

- power lines being down, generators powering water pumping started successfully

- tsunami drowned oldest generators which were laid too low for a tsunami of that scale, backup batteries took charge

- total amount of destruction around caused delays in grid power restoration so batteries eventually went down

- core could not be cooled so it melted down, and fell to the containment vessel

This is a tiny excerpt sequence of only parts of the events, but it can be seen that there were both multiple successes and multiple failures. Had there been a single failure, it would have stayed quite safe, but the cascade of events led to the disaster we know.

Actually, nuclear power plants are designed to withstand failure. Typically there are multiple backup plans to safeguard against failure of any one system. One comment I sometimes hear is, "They had to pump seawater in to cool things down? That's crazy! They should have had a backup plan." It turns out that nuclear plants are intentionally built near bodies of water because external cooling is a backup, should the primary cooling systems fail.

Nothing, however, is designed to withstand systematic catastrophic failure of all of your backup plans.

>> Fukishima plant

Actually it sounds like the plant failed due to some poor - in retrospect - design assumptions. The generators required to keep cooling systems running safely were buggered by the same disaster.

"fail-over" - they got it half right.

The problem is when the backup system is not independent of the primary, so one failure takes out the other. When I read about the step-by-step domino sequence of failures in the plant, the design was clearly deficient.

The erroneous thinking was "the tsunami wall cannot fail". The correct thinking is "what happens when the tsunami wall is breached? what happens to the plant? how can the plant withstand that?"

For example, the most obvious thing is to harden the backup diesel generators against flooding. This would not have been difficult nor expensive. Another solution would have been to have those generators located at some distance from the plant, so they could be repaired without irradiating the workers, and so a disaster at one would be less likely to affect the other.

Another obviously poor design was to have the emergency hydrogen venting go into an enclosed space, where it can build up and explode, rather than venting it outside.

I don't know what your background is but, based on your post, I am assuming it is not in civil or mechanical engineering. Please excuse me if I'm wrong.

The design of this power plant probably went like most designs in civil engineering where extreme design loadings were defined (500-year quake, 100-year flood, etc.) and the plant was designed to meet the loads that would be imposed by the most critical event. For a critical piece of infrastructure these loading conditions are quite stringent. While these loadings drive the design at one end, budget drives the design at the other. Most civil projects tend to be just safe enough and not more. This leads to the realm of acceptable risk/failure. The tsunami wall failing under a 1000-year quake is an acceptable failure. The backup systems were most likely designed for progressively lower degrees of acceptable failure. At some point though it becomes too costly to over-design.

Was hardening the backup generators against flooding "not difficult nor expensive"? I can't tell you that, I didn't design it. Based on the fact that they weren't hardened, I would say that it probably was difficult or expensive.

Would placing the backup generators off site be a better idea than having them on site? Possibly. Possibly not. Every meter you move the generators away from the plant is another meter's worth of risk. How many redundant transmission lines do you need for a generator a mile away? How many redundant generators do you need now that you have the added risk of possibly losing a generator's transmission lines?

Contrary to common belief, public works projects do not have an infinite budget. On top of this, working with municipalities generally results in ridiculous amounts of regulations regarding pricing, reviews, and permitting. While this maintains a minimum standard for designs, it also drives all designs down to that minimum standard. It is simply too costly to continually design for more and more unlikely events.

Users of this site should be well familiar with this based on the number of Internet Explorer compatability comments I've read lately.

My background is I am an ME and I worked on designing flight critical systems on airliners. I had the philosophy of designing to survive failure hammered into me, and when I see the Fukishima plants, all the red flags go up in my head.

For example, let's assume the wing spar fails. Junior engineer says "but the spar can't fail! We designed it to handle any predicted load!". Senior engineer says "Wrong answer. Anything can fail. How will you design the airplane to survive a wing spar failure?" (The solution usually is to have dual wing spars.)

This question is repeated for every single system and part in the airplane. Failure scenarios are also played out to ensure that failure of one part or system will not have a "zipper" effect of breaking other critical systems.

With Fukishima, I clearly see "the sea wall cannot fail, so we won't even bother to investigate if we can make failure of the wall survivable."

As it turned out, it would have been survivable if only the backup generators hadn't failed due to flooding. Hardening those generators (one way) is to simply put them in a concrete box. It's hard to believe that would have been that expensive. Videos of the tsunami showed a lot of masonry structures withstanding it.

> How many redundant transmission lines do you need for a generator a mile away?

Good question. The general rule is to have an independent backup system for every critical system. That has made flying around the world in an airliner safer than driving yourself to the post office.

Nuclear power plants and oil rigs are also designed to withstand failure.

This was always awesome to me. I knew it perfectly from the moment I saw the ashtrays that it was a conscious and genius decision for the human-centered system of an airplane.

This has business implications more than UI implications, I think. We don't question airlines when it comes to safety regulations, pilot time off, good amounts of rest, all that. We regulate everything liberally. Air travel is a system designed like clockwork for every single variable and every single complex input. And it works nearly flawlessly.

Yet, in business—even in the best businesses—we expect far more of individual people than they are capable of, instead of improving the systems they're in. You have to control for both, and design for the realities of business and work; even the human ones. Don't believe in myths, don't depend on rockstars, and prepare for anything. Improve your systems as if it was as important as air travel. Your employees are great, but put ashtrays in the bathrooms so they don't set the plane on fire. So to speak.

For those interested in systems thinking and especially how it relates to people and business, look up W. Edwards Deming and read at least his 14 points. Read "Out of the Crisis" for more. Personally I think systems thinking needs to be more prevalent in business today, but we're still a very individualist society so it's very difficult to make the leap. Something to consider as well.

I was thinking about this same idea earlier today: Buses in Philadelphia have a bunch of "No Eating and Drinking" signs and consequently no trash cans. The result is that the back of the bus is covered in trash. If they had just 1 or two trash cans it would be a much more pleasant ride.

I have never seen a city bus with a trash can.

Chicago's CTA busses have garbage cans in front of the rear exit doors. But then again we also have alleys so we don't have to put our garbage out on the sidewalks.

We have them in Norway

In London too

The people who throw trash on the back of a bus are not the people who would throw that trash in a bin in the bus.

I disagree. When you're on a bus for a long time and the option is either to sit with whatever trash you have on your lap/put it in your bag etc, or drop it, you may well drop it. If there's a trash can conveniently located, most people would place their stuff in it.

It's not foolproof. There are people who toss trash around regardless. It's a question of making people go out of their way to do something vs allowing them to do it easily.

Fire hazard maybe? Trash cans were removed from commuter trains in Stockholm since they were constantly being set on fire. They're on our buses though.

Go to England and you won't see trash cans in train stations at all.

In England we do have bins in stations, but now days they generally consist of a transparent bin bag with no surrounding material (e.g. held open by a loop at the top that's attached to a wall). I believe the logic is that it makes it harder to hide a bomb in them, though whether this is fact or just commonly quoted myth I have no idea.

Partly correct. Trash cans were removed to prevent people hiding bombs in them. They are now coming back, both as transparent plastic bags, and also as bomb-proof cans (which are designed to direct the explosion upwards, and resist sideways rupture).

Well, that has been the case in France since 1993 (bomb attacks in the Parisian metro).

And that was also the explanation I had been given, so I'd say it's probably true.

Last time I was flying they had removed the bins from the waiting area (because terrorists). I almost wished I left the trash on the seats or not taken care to make it easy to remove -- that is the only way they will stop doing stupid shit like that.

The solution to that is to make the driver responsible for cleaning his bus, and also to give him the right to eject people that doesn't follow the rules.

Drivers are not conductors and I doing one job is hard enough, now you think they should have 3?

It's probably cheaper to have a trashcan onboard than an armed driver. Yes, when you threaten people with ejection sometimes they threaten you right back.

Huh? Drivers are gatekeepers that let people onto the bus and validate that the people that enter the bus have tickets.

If people don't respect what the driver says, the driver should stop the bus, and call security and then not move until the issue is resolved. There should be no tolerance at all for people that threatens the driver.

The driver isn't a gatekeeper or tollbooth collector. They stop, you pay your fare. You don't pay the fare they aren't going to argue with you, just pull off to the next stop. Because the bus driver has a schedule to keep and if he has to stop the bus for every minor infraction (and eating on the bus is very far down that list) than the schedule becomes unreliable, people stop taking the bus, and then revenue drops.

And all of this could have been avoided with a trashcan on the bus.

If you've watched anything on youtube you'll see that people escalate a situation for some of the stupidest things. The world is full of crazy people and they drive or take the bus too.

"You don't pay the fare they aren't going to argue with you"

Where does that happen?

I see it all the time in a bunch of cities. The driver isn't going to chase you to the back of the bus if you walk by him. I've had drivers tell me to just go ahead when I didn't have the right amount of change ready.

> Huh? Drivers are gatekeepers that let people onto the bus and validate that the people that enter the bus have tickets.

There are many cities where you can enter through any of the bus' doors.

Drivers always have the authority to eject passengers. If they get resistance, they call the cops.

I'm not sure when they would clean a bus though. I'd rather have my bus driver drive than stop to pick up rubbish.

...and then when the driver of $ethnicityA kicks off a passenger of $ethnicityB, there's a lawsuit and we're back to square one.

wow, seriously? are you by chance a congressman or lawmaker of some sorts?

No, but I live in a country where this is how it works. Drivers here in sweden are responsible for cleaning the bus during the day (with a more thorough cleaning at the garage that the driver isn't responsible for, afaik), and he has enough authority to eject people off the bus if they are violating rules, or to not let them on if they would violate rules.

I like Sweden. But this has to be one of the most bureaucratic approaches to solving the problem. And it's ripe for abuse.

As I understand it, aside from the cleaning, it's the same in America. But if a driver pulled over in the middle of rush hour traffic to kick someone off a bus because they put down an empty can of soda, they'd be torn to shreds before they made it back to the driver's seat.

"they'd be torn to shreds"

Where are you taking buses that the passengers are so rage-filled?

New York City.

If an errant cigarette is enough to bring down a plane why does the TSA strip search me looking for a bomb?

I bet you could get a pretty roaring fire going using the 120v outlet and all the paper goods provided in the bathroom.

Because, although it could bring down a plane, it's very likely not to. The fire will be detected quickly and then put out.

Your question is sort of like asking, if an airliner can fly on one engine, why do they bother putting on two? The answer, quite simply, is robustness.

My point is that it is very unlikely anyone will try. There is exactly nothing stopping anyone from packing an airplane bathroom with alcohol soaked paper towels and lighting it on fire; and yet it has not ever happened. The TSA is a colossal waste of time and money - the more ways that it can be pointed out the better.

I don't like the TSA's approach either, but this isn't a very good argument. They stopped disallowing lighters on flights for this reason; they don't want to care about the small threats and focus on finding...you know...terrorists. The change hasn't soaked in completely yet, but their is hope they'll do the right thing eventually.

It would be fairly easy to put your fire out with a fire extinguisher. But I'd rather not fly with you anyways :)

Aren't matches still allowed?

Yes, they are. "One book of safety (non-strike anywhere) matches are permitted as carry-on items, but all matches are prohibited in checked baggage."

Even better - matches aren't easily picked up by the X-ray machines.

They were until you just mentioned it.

If the TSA allows lighters now, I imagine they also allow matches.

The other reason for it is to make people feel safer about flying on planes. I think it has long outlived its usefulness for that purpose, but that may be my bias toward rationality speaking.

I always assumed the reason for the intrusive security checks was that at some high level, our government felt another terror attack was very likely, and they didn't want anyone to be able to say they weren't doing anything after it happened again. So perhaps it is to prevent rioting in the streets after an attack as much as to prevent the attack itself.

  Then the bleeding-heart liberals attacked in 1988,
  complaining about their “filthy air” and their “lung cancer”.

  This was, of course, the thin end of the wedge. 
  In 2000, the FAA banned smoking on commercial 
  planes altogether. Talk about a bunch of buzz-kills. 
Really? Does anyone actually think this was a bad idea? Forget the "filthy air" or "lung cancer", exposure to smoke can seriously aggravate asthmatics and other folks with respiratory conditions, not to mention cause respiratory conditions in children. Surely smokers can abstain for a few hours instead of exposing everyone in a confined space to their cigarette smoke. I'm at a loss as to why anyone would complain about this.

I took it to be sarcasm. Anyone that puts "lung cancer" in scarequotes has to be joking.

I assure you, it was sarcasm.

And Poe's Law strikes again.

On the other hand, yeah, there are people who honestly think that those regulations are a bad idea that bring us farther down the Road to Serfdom and the ultimate death of Western Culture.

I always forget the name of Poe's Law, thank you.

You can see the same principle in a lot of places. This makes me think of a passage I recently read about the legal system in Germany:

…Unlike many developing countries, German legal doctrine and practice avoid this result. German regulatory violations seldom void contracts, and German prosecutors seldom act on regulatory violations revealed in a civil trial. Thus a gardener in the German gray market who does not pay taxes can sue an employer for unpaid wages without fear of triggering regulatory prosecution. And a customer who buys a restaurant meal at an hour when law requires the closing of restaurants still has to pay his credit card bill. The same applies for a construction contract that violates zoning regulations, or a credit contract that violates banking regulations. Although seldom discussed in constitutional law, separating the civil courts from the regulators and police is an important part of the separation of powers, especially in countries with a large gray market.


That's generally true of most first world countries, including the US and the UK.

Contracts can be broken if they would require an illegal act (i.e., a "crime"), but regulatory infractions generally are not sufficient.

http://www.marco.org/2012/02/25/right-vs-pragmatic is a similar example. It's important to cater for what people are going to do rather than what you think they should do.

It seems to be down now.

Here's the text if it continues to not work:

I’ve been lucky enough to have the chance to fly a lot over the past year or so. Working with Stephen Foskett and the rest of the Tech Field Day crew means that I’ve been to California almost every month. That’s a lot of flying.

One of the things that I’ve noticed on my flights is that they don’t want you to smoke. You actually used to be able to smoke on planes, which seems weird now that you can’t even smoke outide.

I’m not a smoker, so it doesn’t bother me. (As an adorable aside, when I was five years old, I literally glued hand-made no-smoking signs to the walls of my grandparents’ house. They were less than amused.) But the occasional legacy arm-rest with an ashtray harkens back to days of yore when every Joe Cool enjoyed the wonders of aviation while kicking back with a flights as smooth as a Laramie cigarette. He probably got a full meal as part of his ticket, too, the jerk.

Then the bleeding-heart liberals attacked in 1988, complaining of their “filthy air” and their “lung cancer”. The FAA banned smoking on flights less than 2 hours, presumably because the pilots were getting nic-fits after longer than that.

This was, of course, the thin end of the wedge. In 2000, the FAA banned smoking on commercial planes altogether. Talk about a bunch of buzz-kills.

So now we’re flying without cigarettes, and they are not kidding around about this whole “no smoking” thing…all you have to do is open your eyes to see that they don’t want you smoking:

That light is never turned off. I have actually seen a few planes which were new enough that instead of a no-smoking sign say “Please turn off electronic devices”, under the assumption that everyone is already well-trained enough to not smoke, but those are comparatively rare. Nope, it’s mostly the “no smoking signs”. But in case you didn’t look up, here’s the safety information sheet on the airplane. See if you can count the number of “No Smoking” warnings:

And on top of this, there’s a smoke detector in the bathroom (along with a heavy fine for disabling the smoke detector, too!)

No, planes are pretty much set up for not-smoking. Heck, there’s even a “No Smoking” sign on the ashtray in the bathroom:

Wait, what? Yes, you read me right. You’ve probably even seen them yourself. In airplane bathrooms, there is an ashtray (complete with No Smoking sticker) for the people who smoke in the bathroom, even though they shouldn’t.

When I first started bringing this up to people, I encountered the same reaction again and again. People would say, “oh, it just costs too much to replace the door or take out the ashtray”. This is absolutely not the reason, though.

Allow me to quote from the Code of Federal Regulations for airworthiness:

Regardless of whether smoking is allowed in any other part of the airplane, lavatories must have self-contained, removable ashtrays located conspicuously on or near the entry side of each lavatory door, except that one ashtray may serve more than one lavatory door if the ashtray can be seen readily from the cabin side of each lavatory served.

The plane can not leave the terminal if the bathrooms don’t have ashtrays. They’re non-optional.

That’s an awfully strange stance to take for a vehicle with such a stringent “no smoking” policy, but it really does make a lot of sense. Back in 1973, a flight crashed and killed 123 people, and the reason for the crash was attributed to a cigarette that was improperly disposed of.

The FAA has decided that some people (despite the policies against smoking, the warning placards, the smoke detector, and the flight attendants) will smoke anyway, and when they do, there had better be a good place to put that cigarette butt.

There’s a lot of wisdom in a decision like that. I think that it’s a lesson that we can put to use in a lot of the things that we do. There’s a really interesting book on a similar topic, called Nudge.. The idea behind Nudge is that every design decision that you make, as an engineer, affects the way that people behave toward your creation, so you should tend toward design decisions that encourage positive behavior in users.

This is similar to the design consideration called affordance. If you’ve ever walked up to a door and pushed, then realized that the door was supposed to be pulled, even though it looked like it should have been pushed, then you’ve come up against someone who didn’t understand affordance.

Here’s a good image of handles which afford pushing or pulling by Yanko Design:

It’s a cross between form and function. We have “grippy” hands that open flat. We instinctively know how to use things like this because of how we are formed.

You don’t engineer your systems with the belief that none of your computers will ever break. That’s insane; you KNOW they’re going to break. So don’t assume that your users will never break the rules. Build in graceful failure as often as possible, whether you’re designing a user interface or a security policy.

Likewise, when you are designing your infrastructure (or security policies), keep in mind the idea of affordance, and nudge people into making the “right” decision each time. The cynical Hanlon’s Razor says

Never attribute to malice that which can adequately be ascribed to stupidity

Instead of stupidity, maybe people are trying to push on the door that’s supposed to be pulled.

Or, have a gist. With images. https://gist.github.com/2766143

Or https://gist.github.com/2766323, including the final image as well

Ah. Even better.


CloudFlare caches seem to always fail when they are most needed.

I decided to investigate this comment to see if we (CloudFlare) actually had failed while this story was hot.

Bottom line is that the site is on CloudFlare, and during heavy load (probably from Hacker News) the site did go down or slowed a lot. Unfortunately, it's the real web server that died or went very slow and not anything in CloudFlare.

The server appears to still be having problems because if I browse to other pages on the site (e.g. http://www.standalone-sysadmin.com/blog/sysadmin-calendar/) you'll see that CloudFlare's "Always Online" is enabled and showing a cached version of the page. Here's a picture of what that looks like: http://i.imgur.com/QIeQF.png

Is the site only partially cached in CloudFlare or something? Seems like with your "Always Online" feature, a dead server should trigger CloudFlare's "Always Online" feature and show a cached version for all the pages.

We do not cache the entire site with Always Online. The Always Online feature will display a limited cache of the site's content.

Isn't this exactly what "always online" it supposed to prevent?

It worked fine for me until I tried to post a comment, then I saw the caching online/offline issues from cloudflare.

The airlines actually save money by preventing smoking : The air in the cabins needs to be recycled less often. The flip side, though, is that air-bourne diseases are more prevalent on flights now, since the air is rebreathed more often before filtering. Source : Qi series 1 (BBC UK).

Uhh, you know QI is a comedy show, right?

Anyway, it's not true. Air in the cabin is bled off the engines, from the early stage of the compressor, then pressurized and heated. It's not one cabinful of air that was in it from the ground endlessly recirculated.

QI also told the world that the Internet uses GPS to route packets (tho' some devices may use GPS for its clock signal, packets don't know geographically where they are).

It's a comedy show, but that doesn't mean they don't take facts seriously. As I said in another comment further down, QI is:

a show with a team of good researchers, they can on occasion be wrong (and have corrected themselves for mistakes in previous shows in the past), but they won't put a fact into a show without getting good sources for it

So while they may be wrong in this instance, the fact that they are a comedy show isn't reason enough to think so.

How exactly do they save money by not recycling air?

You don't have to pay for air during flight - it comes from the outside air and is free, it's not canisters or something.

You do have to pay for air if you care what pressure it is at. Non-Sherpas will demand a refund of their ticket price if provided air at ambient pressure at 35000 ft.

Actually the issue of pressure is much more complicated

Yes, you can increase the pressure. But then your flying tube in a low pressure environment may explode

Or it'll suffer a bigger expansion/contraction with every cycle and hence less cycles or metal fatigue and failure at 37000feet (passenger won't ask for a refund as they will be unable to do)

So the "cabin altitude" is really a balance between mechanical resistance and people not passing out (though this may be a good idea with some passengers)

Lets do the math then: http://www.wolframalpha.com/input/?i=785+millibars+*+876+cub...

Result: Each air change costs around .62 of a gallon of gas (assuming perfect efficiency). Or around $2.50 - let's call it $10 to account for inefficiency. In contrast it costs around $10,000 per hour (not including salary) to fly a large plane.

Saying they don't circulate air to save money is ridiculous.

Some would say the same thing about removing in-flight beverage service or tossing blankets, pillows, and airline magazines to save weights, yet airlines do it. I think it is equally ridiculous to care about such costs, especially at the cost of focusing management away from the top line, but using logic to suggest it does not happen may not get you far in this case.

Is it to save weight, or to save other costs around maintaining blankets and pillows?

Some airlines make just over $100 per flight. Not per person per flight, PER FLIGHT. They are looking for every saving they can get.

You can work this out my looking at an an airlines profits, and how many flights they did a year.

Life is complicated. So are airlines.

In this case, airlines are a business designed not to have runaway profit. The unions are very powerful. They know how much money the airline is making a demand large percentages of it. They leave a nominal profit for key investors but shareholders as a whole are regularly left out. In fact, if you look at the entire history of commercial flight, the industry is break-even.

That's not a fluke. If costs were higher, unions would get a smaller cut. If costs were lower, unions would take more.

Philip Greenspun has some great writing on this, as well as the old, shortlived but fantastic Enplaned blog.

You are referring, of course, to this excellent (and somewhat frightening) article: http://philip.greenspun.com/flying/unions-and-airlines

There was an episode of the podcast Planet Money where they claimed that the American Airline industry has, as a whole, actually lost money over the course of its existence. As in, overall, net financial loss.

Maybe for small regional flights. My numbers where for huge 400-500 passenger planes.

By my calculations a smaller 70 passenger plane would use around 1/5 the energy per air change, and they typically fly for only an hour or two. So for an air change every half an hour it would cost them around $4 per flight (and that's assuming low efficiency). So $100 profit is still possible (although I have to say that that's amazing low, but I'll take your word for it).

I've heard it has something to do with the air filters. Less smoking = less clogging of the filters = less air filters replacement = more money to airlines. Just heard that, don't know if it's true.

That's what I've been told by SNCF (the French national railroad company) officers when they forbad to smoke in trains.

Setting aside the fact that this source is a random person blogging and quoting a pilot (his job is flying, not dealing with air-con), the fact that airplane air "isn't as disgusting as you think" doesn't mean it isn't more disgusting now than it was when smoking was allowed.

I don't have a source and am too lazy to find one, but it was stated on QI which is a show with a team of good researchers, they can on occasion be wrong (and have corrected themselves for mistakes in previous shows in the past), but they won't put a fact into a show without getting good sources for it, so if they say that air gets recycled less now than when smoking was allowed, I believe them.

That's not what you claimed - you claimed that it was a) recirculated less and as a direct result b) more airborne germs are prevalent and c) cost is saved.

Sorry - it's my fault for not giving more background on Mr. Smith - Patrick Smith has been a Delta Air Lines pilot for about 10 years, written two books on airlines, before that flying cargo, and I've met him more than once, so I'll trust him and the other pilots I've met when they tell me how their airplanes work.

Here's more of his articles on the subject: http://www.salon.com/2009/09/25/askthepilot335/ http://www.askthepilot.com/questions-and-answers/#cX-q9

and another article here: http://airlinesafety.com/articles/FSFCabinAir.htm

I'll allow that it's certainly possible that manufacturers have tweaked the circulation post-smoking, but even if so, it wasn't done with some nefarious intent or to the detriment of passengers. The air we breathe (as I'm about to get on a flight) is incredibly clean, cleaner than in my office.

That's not what I claimed because I didn't claim anything at all.

Your sources are all (I think?) about the fact that the way they deal with air is good, and you may well be right that it's cleaner than in your office. That doesn't mean that it's not less clean than when smoking was allowed - it may well be that in order to get rid of the smell of smoke they needed to clean the air way more than technically necessary, and that therefore after the smoking ban it could be lowered without being "some nefarious intent".

Except the recirculation systems started well before the smoking ban...

I'n sorry, you're right. I confused you with the OP, please accept my apology.

From the transcript (http://sites.google.com/site/qitranscripts/transcripts/1x10) - just the tidbit about 6% savings in fuel cost just by reducing airflow sounds completely implausible:

"Stephen Well, the question is . . . It was almost certainly a bad idea, erm . . . It was a lousy idea, in fact, 'cause when smoking was allowed, the cabin air was completely replaced with fresh air every three minutes, and now, the airlines save money . . . they save up to 6% of their fuel bills by using a mixture of fresh and recycled air--

Julia And SARS.

Peter Ohh.

Stephen --yeah . . . using under half the amount of fresh air needed for comfort; increasing the amount of carbon dioxide in the cabin; causing dizziness, and nausea, and allowing viruses to thrive. Passengers think that, because they can't smell smoke, the air is fresher. This is not so. Apart from anything else, it has dramatically increased the number of air rage incidents. One of the earliest reported incidents of air rage involved a passenger in first class, probably trying to take his mind, erm, off cigarettes, by drinking too much, and he was refused another drink, and so he decided to lodge his displeasure, and shat on top of the food trolley. "

While Patrick Smith may not be an air conditioning expert, as a pilot he's required to know how the AC systems work and how to operate them, and if there was a widespread modification to AC systems or pilot procedures after the smoking ban, I'd expect him to know about it and mention it in the article.

An interesting book I read a while ago on health myths had a very good debunking of that urban legend: http://www.amazon.com/gp/product/B004YD69WM/ref=kinw_myk_ro_...

And enough time goes by without nobody ever seeing a cigarette being smoked midair, the fear of unknown grows (="that isn't normal, what could happen if someone lights a cigarette in an airplane, it could bring the whole plane down!") and then someone freaks out for seeing a pack of cigarettes in someone's pocket, and a few years after that the TSA will require cigarette packs to be removed at the security and kiosks in lounges to only sell cigarettes in sealed containers that must not be opened prior the flight.

And after that, if there's still someone who dares to smuggle these terrorist cancer sticks onto a plane and lights one, he will bring the whole plane down because some FAA rule from 2020 requires immediate landing in that case to the nearest strip to ensure the safety of passengers.

All that, despite the fact that there's still that ashtray in the toilet, non-optionally.

nice message with the real reason for the ashtrays.

one thing that bothered me however, was that push vs pull handle design. if you're really trying to provide affordance, why have a handle at all on a door that needs to be pushed? isnt it our natural tendency to pull on a door handle when provided with one?

all we'd need was a "Push" sign and we'd be done. The shape of the handle hinting how to use it seems subtler than providing the whole door surface as actionable; and if you had to unlock to open, we have well established pushable door designs already.

People frequently don't read signs, which is the point of the affordance design (plus caters to folks who can't read the given language). Also, hands make stuff dirty - you do want something there that's easy to clean, though that can just be a metal plate that can't be pulled.

but you could take the sign away and imo people would still open the door - simply because that seems to be the only thing they could do. plus with the whole door surface being available, why would you use just your hands? use your shoulder or even back (if you happen to be carrying stuff in both hands)!

seems to me like that would be more affordance.

I think the author gives the federal government too much credit. Which is more likely: the government out-witted people by thinking ahead and foreseeing people would break the law, so they write a law to counter it; or, they left the law on the books from when smoking was legal and never amended it? I think the latter.

The "federal government" as in the the FAA knows quite a bit about regulating airline safety. The probability that the FAA left a regulation in there because they just forgot to change it is pretty much 0.

I think you give them too much credit. When I was training to be a pilot some 10 years ago, I remember asking why a lot of regs were in the books. The answer was usually a shrug, or some anecdote about a corner case from the pioneer days of flying.

Perhaps also because there are still airlines in the world (almost entirely in the Middle East and Africa) that still allow smoking.

I don't know about the Middle East. I've flown on just about all the Middle Eastern airlines over the past 7 years, I don't think I've seen a single one that permitted smoking.

Anecdotal evidence (the best kind!) - yes. A friend who went to the National Security Language Institute in Yemen last summer recalled several smoke-filled regional/commuter flights.

Any time you find what you think is an irrational rule in aviation, you can usually trace it back to someone dying.

Not really surprised by smokers not being deterred by multiple warnings not to smoke on planes. Airlines rightly install ash trays to avoid smokers throwing cigarettes into the wrong place creating a real fire hazard.

Remember being on a long haul flight and passenger next to me would disappear to the lavatory clearly sneaking a smoke. He also snuck off to sleep in first class. We have rules in place for the minority of society who lack common sense.

Very good observation. I've never paid attention to the ashtray in the airplane bathrooms and thought they were relic from the plane design in the old days.

I thought they were a relic not of plane design, but from "flight certification" of the lavatories or the doors.

The FAA and the major US plane companies (of which only Boeing is left) made a huge process of flight certifying every little trinket and gewgaw. Once certified, the technology on a plane was essentially frozen, as it was too expensive to certify anything else. I give you the seatbelts and their pressed-steel 50s-style buckles as another example. They look like something Dr Benton Quest developed just after he graduated from college on the GI Bill.

I thought "and their "lung cancer"" was the best part.

The fact that some on HN cannot detect the sense of humor is a little scary.

So in that case, we should put ashtrays in libraries, gas stations and everywhere, so we prevent fire?

Fires on planes are a little more serious. If not stopped quickly, they can spread through the space between the fuselage and the cabin, filling it with smoke. At altitude, they don't have enough oxygen to burn that well, but if it's spread far enough, as soon as you're on the ground the inrush of oxygen will turn it into an inferno in about two minutes (this is why manufacturers have to be able to show that the plane can be entirely evacuated on something like 90 seconds with half the exits blocked.)

Where I've lived, there are ash trays everywhere, not despite; because of laws prohibiting smoking in these areas. The idea is to provide a safe and convenient place to dispose of your cigarette now that you've entered a non-smoking area.

Ok, it makes sense now :)

I can't imagine being stuck in a floating smoke pit. The airlines would have to pay me to fly.

First of all: why airplane toilets called bathrooms?

It's not the airplane; those facilities are simply called by different names in different parts of the English speaking world. Toilet, restroom, bathroom, WC, etc.

Delicate sensibilities. What is that phrase, civilization can be measured by how far we remove ourselves from our sewage? We're so darn civilized now we can't even indirectly refer to shit in polite company.

By the way, toilet is just another euphemism.

And Sweden.

Alternative idea: allow the flight attendants to hand out nicotine patches. :-)

Ryanair sell "e-cigarettes" on their flights.

I've heard of flights saying they're not allowed for various reasons, encouraging people without them to have a normal cigarette being the most unsurprising.

Site is down. A conspiracy by the TSA to bring down those that would thwart security, no doubt. ;)

Nice writeup :D

I'm sure it was, but now it says

"This website is offline. No cached version is available"

Or this gist I made while I had the page up:


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