A United Airlines Boeing 737-900ER aircraft was diverted back to Chicago O'Hare International Airport (ORD) due to cabin pressurization issues on July 3, 2024. The incident occurred approximately an hour after take-off during a scheduled flight UA 343 from Chicago O'Hare to San Francisco International Airport (SFO). The aircraft descended to 10,000 feet and landed safely at ORD.
According to a report by The Aviation Herald, the crew halted the climb at around FL250 before descending and returning to Chicago, landing on runway 27C. A replacement flight reached its destination in San Francisco approximately three and a half hours later without further issues. Data from Flightradar24.com indicates that the typical duration of this route is about four hours.
The aircraft involved is registered as N69830 and is one of United's fleet of Boeing 737-900ERs, delivered in June 2014. United Airlines currently operates 136 such aircraft.