A United Airlines flight departing for Baltimore made a precautionary return to San Francisco after reporting smoke in the cabin on 2 September 2025
United Airlines flight UA2664, operated by a Boeing 737 MAX 9, had conducted a departure from San Francisco International Airport (SFO).
The aircraft was performing a scheduled service bound for Baltimore Washington International Airport (BWI).
United Airlines UA2664 San Francisco-Baltimore
Shortly after the departure, flight crew reported the presence of smoke in the cabin. The climb procedure was terminated and a direct return to San Francisco was carried out.
The aircraft landed without further incident on runway 28R San Francisco International Airport, just under one hour after its initial departure.

The Federal Aviation Administration (FAA) issued a statement confirming the in-flight incident.
“United Airlines Flight 2664 safely returned to San Francisco International Airport around 10:40 a.m. local time Tuesday, Sept. 2, after the crew reported smoke in the cabin. The Boeing 737 MAX-9 was travelling to Baltimore/Washington International Airport in Maryland. The FAA will investigate.”
The airline mustered a replacement aircraft to carry out the scheduled service to Baltimore following the unserviceability.

Flight & Aircraft Data
Flight data shows that flight UA2664 made its initial departure out of San Francisco International Airport at 9:46 AM local time on 2 September.
Following the departure, flight crew then terminated the climb procedure at flight level FL330. A direct return to the departure airport was then carried out.

The aircraft conducting the UA2664 service to Baltimore Washington International Airport was a Boeing 737 MAX 9, registered N37527. This is a 5.9 year old narrow body aircraft belonging to the carrier United Airlines.
It has been operational service with the airline since its initial delivery from the factory in January 2021.
