Boeing's 737 Max jet may remain grounded until 2020 as the US plane maker works on fixing its problematic flight-control software.
The troubled jet is expected to return to the skies in January 2020 under the "latest scenario" although the situation remains fluid and no firm timeline has been set, The Wall Street Journal reported on Sunday, citing unidentified US Federal Aviation Administration (FAA) officials and pilot-union leaders.
Boeing still has to satisfy US regulators that it has answered all outstanding safety questions before the Max fleet can take off, the newspaper said.
Global aviation regulators grounded the 737 Max after the jet was involved in two deadly crashes in October and March that together killed 346 people. Software fixes to the MCAS - an automated system that overrode pilot commands and pushed down the noses of the Max jets that crashed - have been been completed and have been awaiting formal FAA approval for months. But in June, the FAA announced another software glitch it had detected during simulator flight testing, which requires more work by Boeing and is further delaying the Max's takeoff.
American Airlines said on Sunday it would keep the aircraft off its schedule through November 2, two months beyond a previous target of a September return, making it the fifth time the airline adjusted its flights to accommodate the Max's absence.
United Airlines this week also removed the plane from its schedule through November 2.
Tim Clark, the president of Emirates, whose sister airline flydubai is the only UAE-based customer of the jet, said in June he expected the Max was unlikely to fly before Christmas.
The FAA said it is following a thorough process with no timetable, as the agency vowed to resolve all safety issues before allowing the planes back in the air.
Even when the global grounding is lifted, US airlines have said they will require several weeks to prepare stored aircraft to return to commercial operations and potentially retrain pilots.
Carriers already coping with the lengthy Max absence from month to month since its grounding in March are facing the upcoming busy Christmas season with no end in sight for the Max ban.
The grounding of the jet has caused a rift between the FAA, which traditionally led the industry in terms of safety standards, and global aviation regulators who want to conduct their own independent safety checks on the jet.
The International Air Transport Association, the airlines lobby group, has called on global regulators to align their efforts for the safe return of the Max to the skies.
The UAE's aviation authority said earlier it is aware that the FAA is co-ordinating the Max's return to service with European, Canadian and Brazilian regulators.
"We support aligning of efforts of global regulators for working on the Boeing 737 Max issue," Ismaeil Mohammed Al Blooshi, assistant director general of aviation safety affairs, told The National. "We are closely working with the FAA and are in contact with [the European Union Aviation Safety Agency] on the improvements to the aircraft to ensure acceptable levels of safety prior to unbanning of the model in the UAE. It is not possible to provide any timeline at this stage due to ongoing review work."
