• @byroon
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    1 year ago

    This is overly dense and could do with editing but is pretty interesting imo. Here’s my attempt at summary:

    • NATS gets the flightplan in ICAO format
    • they need to extract just the UK part of that flight plan
    • they convert the ICAO flight-plan to ADEXP format, which contains additional waypoints
    • they find the UK section of the ADEXP
    • they now need to convert back to ICAO
    • they try to match the start and end of the UK ADEXP to ICAO
    • duplicate waypoint names exist! The end of the ADEXP route gets wrongly matched with the start of the ICAO route (cos they have the same name)
    • the software recognises this doesn’t make sense, but instead of rejecting this flight plan shuts the entire system down
    • the backup system comes online, and reprocesses the same data, hits the same bug, and shuts down as well