New Delays Could Keep Boeing 737 MAX Grounded Into Holiday Travel Season – The Wall Street Journal

Boeing as a result now has to resubmit briefing documents describing proposed software changes, these people said. The changes then have to be vetted by the U.S. Federal Aviation Administration before a follow-up meeting with the same participants can be held and crucial simulator and flight tests of the final software revisions scheduled.

The upshot, the people said, is likely to be several more weeks of delay that could significantly reduce the likelihood that many of the planes would be back flying passengers in North America during the Christmas holidays, as Boeing and some U.S. carriers have publicly projected. The meetings and the fallout haven’t been reported before.

In Europe, some industry officials say they are increasingly convinced the bulk of the planes on that side of the Atlantic aren’t likely to resume carrying passengers until January at the earliest. European regulators have signaled they might need the extra time to examine anticipated changes to the MAX’s flight-control computers and the automated stall-prevention system dubbed MCAS. Misfires in MCAS led to the crashes of two MAX aircraft in less than five months that took a total of 346 lives and prompted a global grounding in mid-March.

A Boeing spokesman declined to comment on the troubled session last month, which was held in the Seattle area. “Our best current estimate continues to be a return to service of the MAX that begins early in the fourth quarter,” he said, adding that timing will be driven by the Federal Aviation Administration and global regulators. “Our focus is on safety and ensuring the trust and confidence of customers, regulators and the flying public,” he said.

An FAA spokesman said the agency “continues to follow a thorough process, not a prescribed timeline, for returning the aircraft to passenger service.” Referring to various U.S. and international safety reviews under way, he added, “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.”

Some industry officials still believe the latest problems can be resolved quickly enough to have the planes back in the air just before Christmas.

The August meeting was intended to delve into Boeing’s plans to improve safety by having both MAX flight-control computers operating on every flight. The original MAX design, like earlier versions of the plane, relied on a single computer during each trip, making the jet more vulnerable to safety hazards caused by sensor malfunctions or failures.

The apparent discord comes amid signs of additional hitches in the process of getting the green light and FAA certification for the MAX. In recent weeks, Boeing and the FAA identified another potential flight-control computer risk requiring additional software changes and testing, according to two of the government and pilot officials.

Separately, the FAA confirmed that an international group of experts it had assembled, including representatives of nine foreign regulatory bodies, will need more time to document its work and submit recommendations to U.S. certification efforts.

Discussions about MAX pilot training pose the thorniest issues, which both U.S. and European regulators have put off resolving until the end of the approval process. How much pilot training will be mandated—and whether extra simulator time will be required before or after pilots take the controls of the 737 MAX—will be decided by regulators in individual nations and regions.

The FAA and most U.S. pilot-union leaders don’t favor upfront simulator training. European pilots and government officials have said regardless of the decision on simulator training for MCAS emergency response, many aviators on that side of the Atlantic are likely to require some simulator time to comply with other regulatory requirements before they resume flying the MAX.

Boeing since late last year has either submitted, or been on the verge of submitting, three earlier versions of the software fixes, only to be delayed by various technical challenges and questions requiring more analysis and simulator testing.

Airlines are trying to navigate the continued uncertainty about when the plane will return as they plan the final months of the year and prepare for a crush of holiday travelers.

On Sunday,

American Airlines Group
Inc.

said it is removing the MAX from its schedules for an additional month through Dec. 3, but said it remains confident the plane will be certified to fly this year.

United Airlines Holdings
Inc.

announced a similar extended MAX cancellation Friday, saying it will strike the plane from its schedules until Dec. 19.

Both carriers indicated they were confident the jet will be ready to rejoin their fleets in time for the end-of-year holidays. Both had previously aimed to resume MAX flights in early November.

Other carriers such as

Southwest Airlines
Co.

and

Air Canada

have opted not to schedule any flights on the MAX until next year, when they feel more confident regulators will have signed off and the necessary training and maintenance will be complete. It could take upward of six weeks to train crews on new software and procedures and perform checks and maintenance on planes that have been parked since March, a Southwest executive said last week.

Airlines don’t want to run the risk of counting on the plane only to be caught off guard by another delay. People flying to visit friends and relatives for holidays and over school breaks often don’t have much flexibility to adjust plans on short notice, or much patience for last-minute changes.

“By proactively removing the MAX from scheduled service, we can reduce last-minute flight cancellations and unexpected disruptions to our customers’ travel plans,” Southwest said in a statement last month.

U.S. carriers had 72 MAX jets in their fleets at the time of the grounding. That number was supposed to roughly double this year, making it increasingly difficult to work around the plane’s absence.

Write to Andy Pasztor at andy.pasztor@wsj.com and Alison Sider at alison.sider@wsj.com