A United Airlines flight from Zurich to Chicago arrived one escape slide short this week. Flight UA12, operated by a 767-300ER (N666UA), was on final approach to Chicago’s O’Hare Airport when one of its off-wing escape slides deployed and detached from the aircraft, landing in a residential neighborhood east of the airport.
The flight was on final approach to Runway 28C when about 17:27 UTC (12:27 local time) the slide deployed and detached from the aircraft falling into an area resident’s backyard. The location of the incident is approximately 2.72 miles (4.37 km) from the runway threshold.
The slide that fell off flight 12 today and floated down to North Chester in Norridge caught on security cam. Starts at about 12:27:37 you can see it floating down. @nbcchicago @ABC7Chicago @fox32news @WGNNews @cbschicago @UnitedAirlines @CNN @FAANews @ohare @fly2ohare pic.twitter.com/l5OaN4DCkU
— Steven Preston (@streaker_67) July 18, 2023
How could this happen?
Most of the escape slides on the 767-300ER are stored in the doors of the aircraft. Deploying those slides requires the opening of the door while the slide is armed. There are also two off-wing escape slides. These slides are stored in a compartment in the aircraft fuselage just above the aft section of the wing (see highlighted area of photo below).
The off-wing slides ostensibly require the activation of the over-wing exit doors to deploy, but it is possible for the slides to deploy even without the doors opening. A similar incident occurred in 2016, when an Atlas Air 767’s off-wing exit slide deployed and detached while the aircraft was on approach to Phoenix.
The United slide was discovered missing by ground handling personnel after the aircraft landed in Chicago. United says, “We immediately contacted the FAA and are working with our team to better understand the circumstances around this matter.” The FAA, for its part, is investigating how the slide deployed and what, if any, further steps are necessary to prevent future accidental deployments.
How the escape slide works
The video below shows a 767 over-wing escape slide deployment during a maintenance visit.