Nearly six months after Boeing 737 MAX aircraft were grounded in response to two fatal crashes, United States airlines are pushing flight cancellations for the planes out to December and January.
Meanwhile a team of global aviation experts have asked for more time to finish their review into certification of the troubled aircraft.
The US Federal Aviation Administration (FAA) said in a statement on Friday that the Joint Authorities Technical Review (JATR) panel would finish documenting its work and submit its observations, findings and recommendations in coming weeks.
It was expected to recommend major changes to the way the FAA certifies new aircraft
The panel, chaired by the former National Transportation Safety Board chairman Christopher Hart, was comprised of technical safety experts from nine civil aviation authorities (including Australia’s Civil Aviation Safety Authority), as well as the FAA and the National Aeronautics and Space Administration (NASA).
Its work was in edition to the FAA’s review of Boeing’s software fixes following the crash of two 737 MAX 8s from Indonesia’s Lion Air and Ethiopian Airlines, respectively, that killed all 346 people and led to the grounding of type globally in March.
The panel’s focus was on evaluating aspects of the 737 MAX automated flight control system, including its design and pilots’ interaction with the system, to determine its compliance with all applicable regulations and to identify future enhancements that might be needed,” the FAA said in April.
“The FAA continues to follow a thorough process, not a prescribed timeline, for returning the aircraft to passenger service,” the FAA said in Friday’s statement.
“While the agency’s certification processes are well established and have consistently produced safe aircraft designs, we welcome the scrutiny from these experts and look forward to their findings.”
Further, the FAA said that after reviewing all recommendations it would incorporate any changes that would improve certification activities.
The MAX certification was separate from efforts to safely return the aircraft to flight after their grounding, including the retraining of pilots with the new software.
Major North American carriers have extensive numbers of 737 MAX aircraft in their fleets.
American Airlines said in a statement that it was extending its cancellation of 140 MAX flights per day until December 3.
United Airlines has extended its deadline by more than a month with its 737 MAX aircraft out of schedules until December 19, while Southwest Airlines has said previously it had cancelled its MAX services from November 2 2019 to January 5 2020.
Boeing has said previously that it had hoped to receive regulatory approval by October for the updated anti-stall software used on the 737 MAX, known as Maneuvering Characteristics Augmentation System (MCAS), that had been implicated in the Ethiopian Airlines and Lion Air tragedies.
American Airlines said in its latest statement that it remained confident that impending software updates to the Boeing 737 MAX, along with the new training elements Boeing was developing in coordination with its union partners, would lead to recertification of the aircraft in 2020.
CNBC reported on Friday that United Airlines’ revised schedule for the 737 MAX of December 19 was more than a month later than previously expected.
Southwest Airlines said in a statement that with the timing of the MAX’s return-to-service still uncertain, it was extending the MAX-related flight schedule adjustments until January 5, 2020.
“The revision will proactively remove an average of more than 200 weekday flights from our schedule out of our total peak-day schedule of more than 4,000 daily flights,” it said, adding that once certified by the FAA, the enhancements would support the safe operation of the MAX.