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 outside.

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 on a flight 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 about their “filthy air” and their “lung cancer”. The FAA banned smoking on flights less than 2 hours, presumably because any longer and the pilots would be having nic-fits.

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:

As the photo says, it’s a cross between form and function. We have “grippy” hands that open flat. We instinctively know how to use things like this handle 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