So we have been watching Air crash investigations ( http://en.wikipedia.org/wiki/Mayday_(TV_series) ), and it is very interesting to see the depth analysis into all the factors that cause airplane crashes. One common theme that arises is that Bad UX causes actually a lot of airplane crashes; well it is probably not the cause, but it sure helps make bad things worse.

For instance, on a ground controllers display there is a 7 character field next to planes that gives the expected height and the published height of a plane. So in the case of this episode the display of “360-370” meant that the plane was saying it flew at 370, and was supposed to be at 360. If the broadcast stopped the display would be “360Z370” In which case the last broadcast was 370, and the expected was 360. No alarms, no color change, just a character in the middle of a 7 digit string that implies that half of the rest of the numbers is garbage. Now that on its own is not something that will crash a plan, as there is very little reason to turn the broadcast system off. http://en.wikipedia.org/wiki/2006–2007_Brazilian_aviation_crisis

Unless you put the button behind the pilots footrest.

And you display an error message next to the button; presumably below the foot. No alarm, nothing else.

And then you add another plane and you have many dead people spread out over the jungle. And after that there is now an alarm if this system turns off.

Another case had to do with a bad airspeed sensor, apparently some bug build a nest in one. http://en.wikipedia.org/wiki/Birgenair_Flight_301

The system created contradictory warnings, and lacked some warnings which would have been expected. For instance the plane went from over speed into stall warnings, and managed to confuse the pilots into their deaths. A warning of “hey we got conflicting airspeeds” warning and a training scenario are now standard.

Another case had an UX failure on the maintenance side. There were 2 very similar looking modules that gauges fuel reserves, they could actually be swapped out between two different models and would turn on and give reading. The problem was that the readings would be a bit off, and would display the tanks as half full rather than empty if you swapped the wrong module with the wrong plane. Again, this is something that is as easy to fix by putting a key into the socket so they would no longer be interchangeable. http://en.wikipedia.org/wiki/Tuninter_Flight_1153

All of these issues were fixed, and they won’t happen again. That is part of the reason that planes really don’t go down very often these days. Well, they don’t go down very often in the 1^st world where liability has made that unacceptable.

It is interesting to see how these small UX issues end up contributing to these disasters, and the only reason they were discovered is because people died. The death of a person is something that has a near infinite cost associated with it in western civilization and therefore causes a very large and detailed process to get down to root causes and implement changes. Especially when it is the death of 100 people at once.

Looking at the small issues that are the root causes in these airline crashes; these small UX changes that are made to prevent them; it really drives home how much the world must have in every day losses due to lousy UX. It is a great show to watch to learn to analyze problems, and it really gives you a deeper appreciation for UX.

UX is hardly the root cause in any of these, but if it had been better these events would have never made the news, and no one would have died.