United Airlines pulled the Boeing 737 Max from its schedule until Sept. 4, as the worldwide grounding of the popular jetliner threatens to drag on the busy summer travel season for a second year.
The carrier's decision comes one day after Southwest, the largest operator of 737 Max airplanes, said it would keep the aircraft off its flight schedule until Aug. 10.
Boeing has faced escalating pressure since two of its Max jets crashed in under five months, resulting in the deaths of 346 people. The aircraft, the latest iteration of a plane introduced in 1967, was sidelined by regulators in March 2019, and CEO Dennis Muilenburg abruptly left in December.
The planemaker garnered no new sales in January after posting a 2019 loss.
The Max's flight control system -- including the so-called MCAS anti-stall software -- played a role in the crashes of both the Ethiopian Airlines flight that crashed in March 2019 and in the Lion Air flight in October 2018. In both cases, pilots had mere seconds to fight the MCAS function, which forces the plane’s nose downward, after it was incorrectly triggered.
United, Southwest and American were the only U.S. airlines operating the Max when it was grounded.
Boeing is facing multiple lawsuits in both crashes, including one that alleges the planemaker concealed problems and refused to ground the aircraft on its own.