Wednesday, June 20, 2007

No Fly Zone

This headline caught my eye UAL Corp.'s United Airlines, the world's second-biggest carrier, said a computer failure grounded all its flights worldwide for two hours today United fly around 3,600 flights a day, so 2 hours of downtime would affect at least 300 but probably more given that it would leave flights in the wrong place for return journeys and result in knock on delays with availability of landing and departure slots. It may even have caused delays for other airlines who perhaps had to wait for connecting passengers or who were bumped from their slots to make room for UAL planes. Apparently the system that calculates "weight and balance" failed. I'm intrigued that this appears to be a single global system rather than a rule-based system that runs locally (either locally on the client or locally in a region or country). There was another story that it might, instead, have been the system that records when the planes doors open or shut. That sounds even more bizarre. I thought the cabin crew figured out if the doors were shut. Computer failures aren't just a public sector problem even though the press, certainly in the UK, seem to think that they are. Oddly if you google "public sector computer failure" and "private sector computer failure" the results are roughly the same - about 1,050,000 entries each, but even the "private sector" stories seem to refer to the public sector. That said, I expect neither search string is a particularly helpful one.

1 comment:

  1. Anonymous9:09 pm

    If the reports are to be believed, it seems that it was flight fuel calculations that were to blame.

    It is, (for British Airways at least, (if memory serves)) convention to compute a formula for fuel something along the lines of

    "The fuel need for the flight"
    plus
    "Ten percent for wind changes"
    plus
    "Ten percent for go arounds, stacking etc."
    plus
    "Ten percent for emgergencies."

    (There may be others etc.)

    Anyway, it looks like someone thought they had a problem with the software, and it resulted in grounding.

    ReplyDelete