Boeing Commercial Airplanes’ 737 MAX jet’s return to service may not happen as soon as domestic carriers anticipate, according to a Federal Aviation Administration official: FAA associate administrator for aviation safety Ali Bahrami said it’s impossible to identify a date for the agency to approve the twin-engine aircraft’s return to passenger service, though he offered December as a reasonable date.
That would be well past August 3 or 5 (the dates presently indicated by the respective flight schedules of United Airlines and Southwest Air Lines, or even the September 3 date suggested by American Airlines in its flight scheduling.
The Boeing 737 MAX has been idled worldwide following the crash of an Ethiopian Airlines flight in March, which followed an October 2018 crash for Indonesia’s Lion Air. Boeing halted assembly and delivery on the aircraft series (for which it has an order backlog of more than 4,600 aircraft), and the Federal Aviation Administration, European Air Safety Administration, and other civil aviation regulators, as well as commercial airlines, have suspended the aircraft from service.
A total of 346 passengers and crew members were killed in the two incidents, which Boeing has indicated were caused by a Maneuvering Characteristics Augmentation System (MCAS), also known as "anti-stall" software, developed to off-set a side-effect of the more fuel-efficient engines adopted for the new version of the 737: because of the engines’ larger size, the planes’ aerodynamic behavior is altered, and the MCAS is meant to counteract a stalling tendency.
But, it’s been determined that in the two crashes the MCAS software responded to inaccurate flight data and sent the two planes into nose dives that the crews were unable to reverse.
Boeing has developed a software patch to correct the situation, and has completed numerous test flights of the 737 MAX with the updated MCAS, testing different in-flight scenarios.
It’s been reported that the U.S. Federal Aviation Administration has approved the new software, but when it will authorize the 737 MAX jets to return to service is the open question.
EASA and the other regulatory agencies, as well as individual airline, also would have to take steps to restore the aircraft to commercial schedules. That may require testing and clearance for individual crews to operate under the updated control functions.
FAA’s Bahrami confirmed that the agency is under pressure to expedite the 737 MAX’s return to service, but according to a Bloomberg report that will happen only after the software has been reviewed and tested, as well as flight testing and other procedures. Finally, the approval will come “when we believe it will be safe,” Bahrami said.
However, Bahrami also acknowledged the reliability of a statement by Boeing CEO Dennis Muilenburg to indicate the 737 MAX would return by the end of 2019.