United Airlines diverted two flights on May 16 and 17. Technical and maintenance issues caused the diversions.

Flight UA920 from Chicago to London made an emergency landing in Halifax, Nova Scotia. A 33-year-old Boeing 767-300ER operated the flight. Passengers deplaned with no reported injuries.

Flight UAL-271 from Shannon, Ireland, to Newark, New Jersey, returned to Shannon shortly after takeoff. A maintenance issue forced the return of the Boeing 757-200. United canceled the flight. Passengers received overnight hotel accommodations.