A passenger discovered the "big knife" in a seat pocket before takeoff from LAX to Maui, and security was called, according to Hilton's Twitter page.
Calling the incident "scary," Hilton writes, "They just finished the security sweep of the plane. About to board again. So strange a knife got on board. Can't wait to get to Maui."
Law enforcement sources tell TMZ the 4-inch serrated blade appeared to be no threat: the knife was actually a box-cutter belonging to the airline crew.