United Airlines has extended its cancellation of Boeing 737 Max flights until at least November 3rd, the company announced on Friday, which will affect 5,000 flights through September and October.

The airline had previously extended cancellations through September 3rd, following the news that the Federal Aviation Administration had discovered a new flaw in the flight software of Boeing’s 737 Max plane — one that was different from the flaw that led to two deadly crashes that claimed 346 lives. Boeing’s CEO recently acknowledged that the company needs more time to fix this new flaw and that the FAA will have to approve the fix before it recertifies the plane.

Southwest Airlines, which uses more 737 Max planes than its US competitors, tells The Verge that it is sticking to its previous plan of reintegrating the plane on October 1st, pending recertification. In the meantime, it is canceling 150 of its 4,000 daily flights. A spokesperson for American Airlines said the company has “nothing to share at this time” about its plans; American Airlines previously canceled 737 Max flights through September 3rd. (Delta Air Lines does not fly the Boeing 737 Max aircraft.)

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“We have decided to pull MAX flights out of our schedule until November 3,” a spokesperson for United Airlines said in a statement. “During this period, we’ll continue to take extraordinary steps to protect our customers’ travel plans. Moving forward, we’ll continue to monitor the regulatory process and nimbly make the necessary adjustments to our operation and our schedule to benefit our customers who are traveling with us.”

The 737 Max was grounded worldwide in March after the plane’s second fatal crash in five months. The crashes were similar in that they were both largely caused by a piece of software that was supposed to help stop the newer 737 Max plane from stalling in certain situations. This software, known as Maneuvering Characteristics Augmentation System, or MCAS, made calculations based on readings from a single external sensor on the 737 Max. Crucially, it also had no way to know if that sensor was damaged.

In both flights, the planes tried to fight a stall that wasn’t happening. The problem was exacerbated by the fact that the pilots in both crashes didn’t know about MCAS because Boeing didn’t properly disclose the software to airlines in an effort to save money and bring the 737 Max to market more quickly.

Sara Nelson, who heads the Association of Flight Attendants union, said earlier this week that she is not eager to see the 737 Max return to flight. “We’re finding out that Boeing was a very arrogant company that really was allowed to call the shots all the time,” she said.