United Airlines said on Friday it is extending cancellations of Boeing 737 Max flights until January 6, as regulators continue to extensively review proposed software changes to the grounded plane.
The company said it expects to cancel more than 8,000 flights for October, November, December and the first few days of January and that it will monitor regulatory updates and make adjustments accordingly.
Among other US airlines that operate the Max, Southwest Airlines has cancelled flights through January 5, while American Airlines has extended cancellations of Boeing 737 Max flights through January 15.
"We have cooperated fully with the FAA's [Federal Aviation Administration’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", the company said in a statement.
The fast-selling 737 Max has been grounded worldwide since mid-March.
Boeing is planning a revision of the 737 Max software to take input from both of its angle-of-attack sensors in the anti-stall system linked to the two deadly crashes and has added additional safeguards.
The company is also addressing a flaw discovered in the software architecture of the 737 Max flight-control system involving using and receiving input from the plane's two flight control computers rather than one.
FAA Administrator Steve Dickson said in September that the agency will need about a month following the yet-to-be scheduled certification test flight before the planes could return to service.
Reuters reported this week that the flight is not expected before November 1, as the FAA continues to review software changes, meaning the FAA is unlikely to allow its return until late November or December at the earliest.
