My kids and I will be taking UA 989 from IAD-FRA in a few weeks and with a train to catch a few hours after arrival I have begun to track the timing trend for the flight. The past two days the flight has been delayed for approximately an hour and a half each day and the given reason was "cargo loading". I haven't seen that before as a delay reason and was curious if others had or if this was common on certain routes or flights. I am not really worried about missing the train as we can always take the next one, just more curious about "cargo loading" delays and their frequency.