What happened
On July 30, 2025, at 1723 mountain daylight time, a Delta Air Lines Airbus A330-941, registration N422DZ, was in cruise flight at 37,000 feet near Creston, Wyoming, when it encountered severe turbulence. The aircraft was operating as a scheduled international flight from Salt Lake City International Airport (KSLC) to Amsterdam Airport Schiphol (EHAM).
Prior to the event, the crew had noted predicted turbulence over the mountains east of Salt Lake City. While climbing through FL350, the crew observed light cirrus clouds and noted that weather applications showed no immediate threats. As the aircraft climbed to FL370, the crew requested a deviation to avoid weather buildups. Air traffic control suggested a left turn to a heading of 350°, which the crew accepted after assessing the radar and horizon.
Following the turn, the aircraft experienced an overspeed event, exceeding the maximum operating speed by approximately 15 to 20 knots, alongside an updraft that lifted the plane to FL380. During this 20-second period, the autopilot disengaged. The aircraft then underwent a rapid descent to FL355, followed by a series of climb and descent cycles lasting two to three minutes. This turbulence caused the aircraft to re-enter a cloud layer. The pilot flying initiated the All Attitude Upset Recovery Strategy procedure at least once before successfully re-engulations the autopilot.
During the event, the aircraft sustained minor damage to interior components. The crew declared an emergency and diverted to Minneapolis-St Paul International Airport (MSP). Upon landing, the crew noted that the right main landing gear brakes were hot.
Among the 246 passengers, 24 were evaluated by medical personnel, with 18 transported to local hospitals. There were 0 fatalities. Of the 10 cabin crew members, 2 sustained serious injuries and 5 sustained minor injuries, while 3 remained uninjured. The 3 flight crew members were not injured.