'Level 3 threat' aboard Newark-bound flight forces emergency landing | 1 March 2024 | A United Airlines flight traveling from London Heathrow to Newark Liberty International Airport diverted to Maine on Friday morning due to a Level 3 threat on board. Flight UA 883 landed at Bangor International Airport at 9:59 a.m. -- nearly 90 minutes before it was supposed to arrive at Newark, according to Flight Aware. The flight was diverted to remove an unruly passenger, Flight Radar reported, citing air traffic control feeds.