Lyn Montgomery, president of Transport Workers Union Local 556, the union representing Southwest flight attendants, called the airline’s decision to resume alcohol sales “both unsafe and irresponsible” in an emailed statement.

According to unruly passenger data from the Federal Aviation Administration, the number of investigations the agency initiated spiked from 146 in 2019 and 183 in 2020 to 1,099 in 2021. Of the 5,981 unruly passenger reports the FAA recorded last year, 73 percent (4,290) involved mask-related incidents. The FAA said in August that alcohol played a role as well.

“We have adamantly and unequivocally informed management that resuming sales of alcohol while the mask mandate is in place has the great potential to increase customer noncompliance and misconduct issues,” Montgomery said.