Southwest Airlines announced on Sunday that it will conduct an internal investigation into an alleged incident on a Friday morning flight, in which a pilot signed off an inflight announcement with the phrase, “Let’s go, Brandon!” The statement, which has become synonymous with anti-Biden sentiment, was implicitly condemned by the airline, which said in a statement that “Southwest does not condone Employees sharing their personal political opinions while on the job serving our Customers, especially when comments are divisive and offensive.” The company also distanced itself from the incident, noting that “one Employee’s individual perspective should not be interpreted as the viewpoint of Southwest and its collective 54,000 Employees.”

The pilot’s Friday statement elicited “audible gasps from some passengers” on the Houston-to-Albuquerque flight, according to an AP journalist who was onboard. The phrase has its origins in a viral event at Alabama’s Talladega Superspeedway in early October, when an NBC Sports journalist misreported that a crowd shouting, “Fuck Joe Biden!” were chanting, “Let’s go, Brandon!”