Southwest launches investigation into pilot reportedly using anti-Biden phrase on flight

(CNN Busienss) Southwest Airlines (LUV) says it is launching an internal investigation after a report that one of its pilots used anti-Biden slang over a plane's public address system during a flight.

"Southwest does not condone Employees sharing their personal political opinions while on the job," the airline said in a Sunday statement. "Southwest is conducting an internal investigation into the recently reported event and will address the situation directly with any Employee involved while continuing to remind all Employees that public expression of personal opinions while on duty is unacceptable."

The Associated Press, which had a reporter on board the flight, first reported that a pilot of a Friday flight from Houston to Albuquerque ended his typical greeting to passengers with the phrase "Let's go Brandon," which has become right-wing code for "F**k Joe Biden." The AP report said passengers responded with audible gasps.

Last week, the union representing United Airlines (UAL) pilots said in a memo obtained by CNN that an in-flight radio frequency meant for emergency transmissions "is not to be used as a personal pulpit."

Captain James Belton of the United chapter of the Air Line Pilots Association told CNN that the memo was related to "Let's go Brandon" being transmitted on the emergency radio frequency 121.5.

"Anyone making these calls is directly interfering with safety," the memo said.

Multiple reports say the phrase relates to a NASCAR crowd chanting "F**k Joe Biden," while driver Brandon Brown was being interviewed following a victory. The reporter interviewing him had at first speculated the crowd was chanting "Let's Go Brandon."