United is pulling the jets off its schedule until March 4, the company said Friday. It expects to cancel approximately 5,100 flights in November and December and roughly 3,468 flights in 2020.
"For more than 90 years, the safety of our customers and employees at United has come first, which is why we have cooperated fully with the FAA's independent review of the MAX aircraft, and we won't put our customers and employees on that plane until regulators make their own independent assessment that it is safe to do so," said the airline in a press release.
The airline joins Southwest Airlines and American Airlines, which also pushed back their respective return-to-service dates last week. Southwest announced that it will remove all 737 Max planes from its flight schedule through March 6, while American Airlines said it will delay commercial use of the aircraft until March 5.
United had previously grounded its fleet of 14 737 Max planes through Jan. 5.
Boeing, meanwhile, has continued to suffer from the worldwide grounding of the 737 Max. The manufacturer delivered only 20 commercial jetliners in October, while its net orders for the year fell to 45 in the same month. Boeing came under further pressure in late October after documents surfaced detailing that engineers raised concerns about the 737 Max's faulty MCAS flight-control system before two fatal crashes that killed 346 people, one in October 2018 and one in March.
Pending approval by regulators, Boeing said it anticipates resuming 737 Max deliveries as soon as December and could resume commercial service in January.