Oct. 17 (UPI) -- Southwest Airlines said Thursday it has pushed its fleet of Boeing 737 Max 8s off schedules into February, as the grounded aircraft's return-to-service is not yet known.
Southwest had planned to return the troubled model in January. Thursday, the carrier said that has been postponed until Feb. 8.
Southwest and American Airlines are the only U.S. carriers that own 737 Max 8s, the model grounded last spring due to two crashes overseas that killed nearly 350 people. The Max 9 version was also barred from flight as a precaution.
"By proactively removing the Max from scheduled service, we can reduce last-minute flight cancellations and unexpected disruptions to our customers' travel plans," Southwest said in a statement. "The limited number of customers who have already booked their travel and will be affected by our amended schedule will be notified of their re-accommodated travel."
American and United, which owns a fleet of Max 9s, said last week they don't expect to fly them again until January.
Boeing has said it's working on a software fix for the 737 Max that influences the automated flight system, which investigators say was the cause of the crashes. The Federal Aviation Administration will need to approve Boeing's fix, whenever it's made.
Postponing the Max 8 return will affect about 175 daily flights out of more than 4,000, Southwest said.
"We offer apologies to our customers impacted by this change, and we thank them for their continued patience," the carrier said.