Join IEEE Spectrum editors on 27 Oct. at 1pm ET for a conversation on social audio app Clubhouse.

Close bar

Washington DC Metro Crash Update

Looking More Like A Computer System Problem

2 min read
Washington DC Metro Crash Update

A bit more information came out in the Washington Post about the possible cause of the Washington DC Metrocrash that killed nine and injured nearly 80 people came out yesterday afternoon. The National Transportation Safety Board (NTSB) said that it found "anomalies" after performing standardized tests in one of the sensor circuits along the track where the crash occurred that communicates information to a subway car as well as back to Metro's central computer system. 

The Washington Post also reports that: "A senior Metro official knowledgeable about train operations said an internal report confirmed that the computer system appeared to have faltered."

Not sure what "falters" exactly means, however, since it wasn't explained in the story.

The NTSB also confirmed that the operator did apply the trains brakes, but they have not been able to determine yet for how long. Nor have they said whether the train operator, who was relatively inexperienced (she was 18th from the bottom of 523 operators in seniority), was distracted or not.

Even if she wasn't, it does bring up an interesting issue of humans being the last line of defense in a computer controlled system. If you were sitting as operator in that train, and it started to move on its own, how long would it be before you noticed that it shouldn't be moving, that in fact a serious anomaly occurred?

As an inexact example, how long is it before you recognize that a pause in your PC's operation means that there is a problem, rather than it just being slow? 

So, if you were a new train operator, what would you believe? The computer that was supposed to control the train, and which probably had always "worked" before or what is in front of your eyes? And would your first thought be that the computer malfunctioned, or something that you did (or didn't do)?

Shades of the Vincennes incident.

I'm speculating of course, but I wonder if experienced Metro train operators who were around since the 2005 Metro computer incident would have caught on that something was wrong a little more quickly.

I trust the NTSB will look at Metro operator training in regard to dealing with computer anomalies. I would also be curious on how much time the operator had driving a train on manual versus in automatic, computer controlled mode.

It will be interesting to see whether crash investigators determine that the flight crew for Air France Flight 447 may have got caught out by a computer problem that went unrecognized until it was too late.

There is a very, very old joke about airlines of the future having only two occupants in the cockpit, a dog and a pilot. The pilot is there to feed the dog; the dog is there to bite the pilot if he touches anything.

Maybe we need another dog to bite the pilot if he or she doesn't touch the controls when necessary.

 

The Conversation (0)

Why Functional Programming Should Be the Future of Software Development

It’s hard to learn, but your code will produce fewer nasty surprises

11 min read
Vertical
A plate of spaghetti made from code with a single strand of "spaghetti code" being pulled from the top of the frame in a neverending loop on a blue gradient background.
Shira Inbar
DarkBlue1

You’d expectthe longest and most costly phase in the lifecycle of a software product to be the initial development of the system, when all those great features are first imagined and then created. In fact, the hardest part comes later, during the maintenance phase. That’s when programmers pay the price for the shortcuts they took during development.

So why did they take shortcuts? Maybe they didn’t realize that they were cutting any corners. Only when their code was deployed and exercised by a lot of users did its hidden flaws come to light. And maybe the developers were rushed. Time-to-market pressures would almost guarantee that their software will contain more bugs than it would otherwise.

Keep Reading ↓Show less
{"imageShortcodeIds":["31996907"]}