United Airlines has cancelled another month’s worth of flights scheduled to operate with Boeing Commercial Airplanes’ 737 MAX jet. The airline, which operates 14 of the dual-engine aircraft, now has suspended use of the 737 MAX until August 3. It indicated that the cancellations amount to 40-45 daily flights.
Rivals Southwest Airlines previously had canceled flights to operate on its 31 737 MAX jets through August 5, and American Airlines has cancelled flights on its 24 737 MAX aircraft through mid-August.
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 737 MAX (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
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 developed to off-set a side-effect of more fuel-efficient engines adopted for the new version of the 737: because of the engines’ larger size, the planes’ aerodynamic behavior is altered.
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 and will authorize the 737 MAX jets to return to service by late June. Individual airlines then would be expected to restore the aircraft to their schedules – and that may require testing and clearance for individual crews to operate under the updated control functions.