Story from AVH (Thanks !)
A United Boeing 767-300, registration N666UA performing flight UA-3 from Chicago O'Hare,IL (USA) to Zurich (Switzerland) with 162 people on board, was enroute at FL330 about 260nm northeast of Chicago when the crew decided to return to Chicago reporting they had uncontained heat and smoke on the flight deck. The aircraft descended to FL240 and landed on Chicago's runway 28R about 45 minutes after leaving FL330. The aircraft vacated the runway and stopped for an inspection by emergency services asking them to check for any fire and smoke, they had uncontained heat and smoke on the flight deck. About 45 minutes after landing the aircraft taxied to the apron.
A replacement Boeing 767-300 registration N657UA reached Zurich with a delay of about 6.5 hours.
(and ironically.................)
The occurrence aircraft had dropped an evacuation slide on approach to Chicago 9 days ago, see Incident: United B763 at Chicago on Jul 17th 2023, dropped evacuation slide in flight and is currently still on the ground in Chicago about 21 hours after landing.
https://flightaware.com/live/flight/UAL3/history/20230726/2100Z/KORD/LSZH
