American Airlines has canceled all scheduled flights with Boeing 737 MAX jets through September 3, extending the grounding of its fleet after two crashes involving the same aircraft model killed 346 people. The airline had previously canceled all 737 MAX flights through August 19 as it awaited recertification of the aircraft in the wake of the crashes. American Airlines operates 14 of the 737 MAX aircraft, and is canceling 115 flights a day as a result of their grounding.