United Airlines won't fly Boeing 737 Max until June

Dec. 20 (UPI) -- United Airlines will not fly Boeing's 737 Max aircraft until June at the earliest, two months later than rivals Southwest Airlines and American Airlines, the company announced Friday.

The planes were grounded, worldwide, in March after two crashes killed a total of 346 people. Investigations of the crashes led to discovery of potential software and design flaws in the plane.

United pulled the planes from its schedule through June 4, a change in a plan announced in November to bring the plane back in March. A prior announcement in October said the planes would return to service in January. Moving back the date gives the airline more flexibility in scheduling and is meant to assure passengers when tickets for summer trips are purchased. However, up to 108 flights per day will be cancelled.

Southwest and American, the other major U.S. carriers using the plane, similarly announced its curtailment of the 737 Max last week, both with target dates of April for resumption of service. Boeing indefinitely halted production of the plane, currently scheduled at 42 per month, beginning in January. In an aviation industry ripple effect, Spirit AeroSystems, a Boeing subcontractor building 737 Max fuselages, announced it will also suspend production, despite 50 percent of its current revenue derived from building the components.

"Since the grounding of the Boeing Max aircraft in March 2019, United has gone to great lengths to minimize the impact on our customers' travel plans," United said in a statement. "We've used spare aircraft and other creative solutions to help our customers, who had been scheduled to travel on one of our Max aircraft, get where they are going. During this period, we'll continue to take extraordinary steps to protect our customers' travel plans."

Federal Aviation Administration Chief Administrator Steve Dickson said last week that the agency has no plans to recertify the 737 Max for use in 2019.