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Boeing Finds New Software Problem That Could Complicate 737 MAX's Return — Update

By Andy Pasztor 

Boeing Co. said it is grappling with a new software problem before its 737 MAX aircraft can return to service, one that industry and government officials said prevents the jet's flight-control computers from powering up as required prior to flight.

The glitch, which Boeing said Friday it was working to correct, is the latest in a string of unexpected technical issues that have complicated and delayed the grounded fleet's return to the air over many months -- and now threaten another schedule slip.

A Boeing spokesman said: "We are making necessary updates and working with the FAA on submission of this change, and keeping our customers and suppliers informed."

Before the problem was discovered last week, according to people briefed on the details, the company and the Federal Aviation Administration were slated to conduct a key certification flight by the end of January. But at this point, these people said, that date increasingly looks like it will slip into at least February.

The length of the delay will largely depend on how long it takes Boeing engineers to resolve and then verify that the specific problem has been eliminated, though coordination with international regulators and other factors could complicate the process.

The problem occurred as engineers were loading updated software -- including an array of changes painstakingly developed over roughly a year -- into the flight-control computers of a test aircraft, one of these people said. A software function intended to monitor the power-up process didn't operate correctly, according to this person, resulting in the entire computer system crashing. Previously, proposed software fixes had been tested primarily in ground-based simulators, where no power-up problems arose, this person said.

The revised software is intended to fix an automated flight-control system called MCAS that led to two crashes, in 2018 and 2019, that killed a total of 346 people. The system, new on the MAX, misfired in a way that repeatedly and forcefully pushed the planes' noses down, overpowering pilot commands and ending in fatal dives. The company has been developing revised software intended to make the software less prone to such misfires and easier for pilots to counteract.

Boeing also has increased redundancy by having the plane's dual flight-control computers operate throughout each flight, a change that industry and government officials said has entailed more software changes than Boeing initially anticipated

It isn't clear how much of a delay the problematic software could create, since various other regulatory steps including finalizing pilot-training requirements remain in limbo.

U.S. carriers already have pulled MAX jets from their schedules through early June, though industry and government officials project that the planes could start making demonstration flights with airline executives on board weeks before that. The MAX fleet was grounded in March, not long after the second fatal crash.

FAA and Boeing officials were in the midst of analyzing prospects for the latest software revisions when Steve Dickson, the agency's administrator, met with newly installed Boeing chief Dave Calhoun early this week. Neither government nor Boeing officials have commented on that session.

In addition to completion of the software fixes, the MAX's return to service is subject to test flights by a representative group of international airline pilots, along with public comments on the details of extra training for cockpit crews. The FAA also has to approve changes to operating and training manuals, endorse revised emergency procedures and sign off on maintenance and inspections of planes that have been in storage, some for many months. Numerous foreign regulators have signaled they won't approve resumption of passenger flights until their own engineering and pilot-training reviews are finished.

Nevertheless, the coming certification flight is widely considered the next major step to ease the MAX crisis, which has cost Boeing and the global airline industry billions of dollars and disrupted flight schedules around the world. If resolving the most recent software errors takes longer than a few weeks, the MAX's overall return to service timeline could take another significant hit.

Write to Andy Pasztor at


(END) Dow Jones Newswires

January 17, 2020 16:56 ET (21:56 GMT)

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