Grounded Airlines: Human Error vs. Computer Error

The probe into the cause of the American Airlines and U.S. Airways outage last Sunday continues. The computer troubles took down the two airlines for two and three hours respectively.

So, what caused the trouble? Here is an airline spokesperson:

Officials at both airlines, however, said the problem appears to have started early Sunday morning after an employee entering data about a cargo shipment on one of the airlines typed a “bad command.” That set off a chain reaction within both carriers’ systems in which the database used for scheduling crews, dispatching flights and processing baggage became flooded with useless information, preventing proper data entry for upcoming flights, the officials said.

What is it, user error or computer error? If you think it was the former, then you’re of the view that people should be trained not to make a “bad command” that could cause the airlines to, in effect, shut down. That is fine, but it does ratchet training costs through the stratosphere.

If you think it was programmer error, however, then you’re with me. Any software system that could be brought down so catastrophically and for so long by a data entry error is a broken system. All too often what we call user error is really programmer error — users are too eager to accept the blame for things that are not their fault.


  1. Regardless of the actual source of this glitch it highlights the future havoc that might be wrought by viruses or targeted attacks. Oh, this brave new world, isn’t technology great.