A Boeing 737 Max took to the US skies on Tuesday for its first commercial flight since the fleet was ground following two deadly crashes in 2019. The American Airlines gave customers the chance to change flights if they were uncomfortable on the Max. Last month, the US aviation regulator approved changes that Boeing made to an automated flight-control system that was blamed in crashes in Indonesia and Ethiopia that killed 346 people in all. Regulators in Europe and Brazil also cleared the way for airlines to resume using the plane if certain changes were made and pilots were provided with additional training.