Kelly Osbourne Tries Booting Aggressive Pit Bull Off Flight

Kelly Osbourne claims a pit bull attacked her Pomeranian at LAX and it was therefore unfit to fly on the same plane with her dog ... but her complaint fell on deaf ears.

Kelly claimed the pit went after her pooch in an LAX parking lot, and coincidentally the owner of the other dog was on the same flight to NYC as Kelly, and she wanted to bring the dog.

We're told JetBlue did a once-over on the pit bull -- a 1-year-old rescue with service dog credentials -- and determined it was safe to board.

The owner and pit bull were seated about 10 rows behind Kelly and there was no further incident.