US carrier American Airlines will extend cancellations of flights on Boeing 737 MAX flights until 3 December, the company said in a statement on Monday.
American Airlines said in a statement that it remained "confident" that software updates to the 737 MAX, along with Boeing's proposed training developments with union partners, would "lead to recertification of the aircraft this year".
American Airlines added that it was in "continuous contact" with the Federal Aviation Administration (FAA), the Department of Transportation (DOT), National Transportation safety Board (NTSB) and others.
American Airlines said: "American is extending cancellations for the MAX through Dec. 3. By doing so, our customers and team members can more reliably plan their upcoming travel on American. In total, approximately 140 flights per day will be canceled through Dec. 3. Our Reservations and Sales teams will continue to work closely with customers who are impacted by these cancellations.
American Airlines has been forced to cancel roughly 140 flights per day and reimburse or reschedule flights for its passengers, and joined United Airlines in efforts to block to plane's return to service after the latter announced it would not use the aircraft until 19 December. The US's third-largest carrier, Southwest Airlines, also said that it would ground all of its 737 MAX 8s through 2020.
Amid ongoing investigations, experts have said that the plane's Manoeuvring Characteristics Augmentation System (MCAS) may have caused the crashes after pilots were unable to control the plane once MCAS had been activated.
Southwest Airlines and American Airlines had received 31 and 24 737 MAX 8 orders, respectively, making Southwest the largest recipient of the Boeing model to date. Boeing has been working to change the MCAS software, with the planemaker struggling to correct the issues beyond its estimations to return the plane to service.
United Airlines also began moving its 14 Boeing 737 MAX jets to Phoenix, Arizona, where they would store them until the planes were ready for commercial flights again, the carrier announced in late August.
US authorities have also vowed to keep all 737 MAX planes out of the skies until issues had been fully resolved.
The FAA would not "not following any timeline for returning the aircraft to service" and that no 737 MAX's would be permitted to "fly in commercial service again" until he was assured that it was "safe to do so", FAA chief Stephen Dickson said during his swearing-in ceremony in mid-August.
A blue-ribbon panel of experts from around the world would need a few more weeks to finish its review of the 737 MAX's recertification, the FAA said on 31 August, with Boeing stating that it hoped to receive regulatory approval for its updated MCAS software, but that it could take roughly one to two months to train pilots to use it. Focus on the aircraft's recertification would remain "separate from the ongoing efforts to safely return the aircraft to flight," the FAA said in regards to efforts from the Joint Authorities Technical Review, according to Reuters.