Boeing Co.’s delay-prone effort to return 737 MAX jets to service has hit a new snag, according to people familiar with the details, due to heightened European safety concerns about portions of proposed fixes to flight-control systems.
Disagreements over various software details, centered on how the MAX’s dual flight-control computers are now intended to start working together, haven’t been reported before. The issue could prolong final vetting of the anticipated changes and may prompt European regulators to withhold their full support when the Federal Aviation Administration ultimately allows the planes back in the air, these people said.
The European Union Aviation Safety Agency recently told senior U.S. regulators it wasn’t satisfied that FAA and Boeing officials had adequately demonstrated the safety of reconfigured MAX flight-control computers, according to people briefed on the discussions. The aim is to add redundancy by having both computers work simultaneously to eliminate hazards stemming from possible chip malfunctions identified months ago; over decades, and on previous versions of the 737, only one computer at a time has fed data to automated systems, alternating between flights. The concerns were passed on by EASA chief Patrick Ky to Ali Bahrami, the FAA’s top safety official, one of the people said.
EASA said it hadn’t reached a verdict on Boeing’s fixes or whether the agency will act in tandem with the FAA.
Without a swift resolution, according to those briefed on the details, EASA’s objections could set an industrywide precedent for foreign authorities publicly second-guessing determinations by the FAA, affecting aircraft initially approved as safe by the U.S.
Boeing and the FAA are finishing testing the dual-computer system, and the final results haven’t been presented to EASA or other regulators. EASA has signaled, though, that it wants additional risk scenarios examined beyond those in the current testing plan, this person said.
The situation remains fluid, and EASA’s position could change. The agency previously indicated it planned to perform some of its own simulator testing and risk analysis in coordination with FAA activities. But now, according to people briefed on the latest friction, European regulators appear poised to diverge from the overall U.S. game plan unless a compromise is hammered out in coming weeks. Boeing engineers are frustrated EASA hasn’t specified what additional measures might allay its objections, according to people close to the discussions.
Regulators are mandating safeguards to the MAX’s flight-control features following a pair of fatal accidents that took 346 lives. The aircraft have been grounded world-wide since shortly after the second crash, in March.
On Monday an EASA spokeswoman said the agency still is assessing the proposed software changes, but she disputed the notion that European regulators are balking at clearing the planes for service simultaneously with the U.S., Canada and Brazil. “At this stage,” she said in an email, “we do not have any specific concerns that would lead to the conclusion” that EASA is avoiding a coordinated response with the FAA. She declined to comment on any conversations between Mr. Ky and senior FAA officials.
Addressing a meeting of foreign regulators in Montreal last month, FAA chief Steve Dickson promised to provide U.S. assistance and to pass along lessons learned “as you make your own decisions about returning the MAX to service.”
Testifying before a House appropriations subcommittee afterward, Daniel Elwell, the FAA’s No. 2 official, also appeared to open the door to the possibility that the jets might return in stages, by region. Mr. Elwell said that “while simultaneous ungrounding, when or if that happens, is desired, it’s not obligatory.”
A Boeing spokesman said “we continue to work with regulators on addressing their concerns and working through the process for certifying the 737 MAX software and training updates and safely returning the airplane to service.”
Chief Executive Dennis Muilenburg said last week Boeing test pilots had completed more than 700 MAX flights. “We are very confident in that software solution, and we are now just marching through the final steps on certifying that, so that everybody’s confident in the safety of the airplane,” he said in a public appearance in New York.
Over the past months, Boeing, EASA and the FAA have basically agreed on related software revisions designed to scale back the power, and reduce the likelihood of a misfire, of an automated system, called MCAS, which led to the two fatal accidents in less than five months.
Lately, the Chicago plane maker has been signaling it expects the FAA to formally lift the grounding in November or December, which would put the bulk of the U.S. MAX fleet on track to begin carrying passengers early next year. It previously said it expected that FAA action early in the fourth quarter. But the company hasn’t yet turned over to the FAA the final package of software fixes. That is expected to be followed by several weeks of FAA analysis, flight tests and determination of pilot training requirements.
The FAA has said it is methodically verifying the safety of proposed fixes but doesn’t have a predetermined timeline for a decision.
After those decisions, it is expected to take months for a carrier such as Southwest Airlines Co. , which needs to phase some 70 MAX jets into its flight schedules, to have the bulk of its aircraft begin carrying passengers. The total includes MAX jets previously flown by Southwest, along with new jets still awaiting delivery.
Timing is especially significant for Boeing, because it is considering whether to further cut production at or temporarily shut down its Renton, Wash., factory while MAX jets pile up in storage. Before the recent concerns expressed by EASA, senior FAA officials were growing optimistic they would be ready to give the green light for MAX flights as soon as early November, according to people familiar with the matter. The friction with their European counterparts is likely to delay that timeline until at least later that month, these people added.
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