American Airlines Group removed the Boeing 737 Max from its schedule for another month, joining carriers canceling flights until December and beyond as they await US approval to fly the grounded jet. The extension means the cancellation of 140 daily flights through Dec. 3, American said in a statement Sunday. The airline “remains confident that impending software updates to the Boeing 737 Max, along with the new training elements Boeing is developing in coordination with our union partners, will lead to re-certification of the aircraft this year,” it said. American announced its decision two days after United pulled the Max from flight plans until Dec. 19. Southwest, the largest operator of the Max, has taken the aircraft out of its schedule through Jan. 5. Air Canada has pulled the Max until January. The Max, Boeing’s best-selling jet, has been grounded worldwide since March 13, following two crashes within five months that killed 346 people. The US FAA is likely to conduct its certification flight for the Max in October, people briefed on the matter said last month. That would broadly match Boeing’s estimate that the Max will return to service early in Q4. Friction between Boeing and regulators worldwide may keep the Max grounded into the Christmas holiday travel season. Aviation authorities, including those from Europe, Brazil and the US, have complained that Boeing has failed to provide technical details about modifications to the Max’s flight-control computers, Dow Jones said, citing government and pilot union officials.<br/>