June 13 (UPI) -- Southwest Airlines announced Thursday it will keep its Boeing 737 Max fleet on the ground through the Labor Day weekend, mirroring a move by the only other U.S. carrier that flies the Max 8.
The airline said it's waiting on Boeing and the Federal Aviation Administration to complete software upgrades and pilot training before it clears the fleet to return. Southwest and American are the only U.S. carriers to fly the Max 8 -- the model involved in two recent crashes in Ethiopia and Indonesia -- and United flies the Max 9. Both variants were grounded worldwide in mid-March.