An Alaska Airlines Boeing 737 MAX 9 operating as flight AS1156 from Seattle to San Diego returned to Seattle-Tacoma International Airport on July 31 after the crew declared an emergency. The aircraft, registered as N964AK, departed at 20:11 local time and halted its climb at about 7,500 feet. According to The Aviation Herald, the crew reported "an electrical smell" in the rear of the cabin during the initial ascent.
The flight landed safely back in Seattle approximately 12 minutes after departure. Emergency crews inspected the aircraft upon landing before it taxied to the apron under its own power. Alaska Airlines arranged a replacement Boeing 737-900, registered N472AS, which completed the journey later that evening. Passengers reached San Diego with a delay of about two and a half hours.
The affected MAX 9 remained grounded overnight and returned to service roughly 14 hours later.