BA Boeing Co

By Andy Pasztor 

U.S. air-safety regulators are set to begin key flight tests of Boeing Co.'s 737 MAX as early as Monday, amid growing expectations by industry and government officials that the planes are likely to return to service around the end of the year.

The airborne checks, slated to be conducted in conjunction with Boeing and scheduled to last three days, mark a preliminary validation and long-awaited milestone for Boeing's technical fixes aimed at getting the MAX fleet back in the air. The planes have been grounded for 15 months following two accidents that killed 346 people, roiled the airline industry long before the coronavirus pandemic and dealt the biggest blow to the plane maker's reputation in its 103-year history.

In an email the Federal Aviation Administration sent to congressional staffers Sunday, the agency said the effort "will include an array of flight maneuvers and emergency procedures to enable the agency to assess" whether a series of software and hardware changes complies with safety certification standards.

But as expected, the FAA stressed agency officials haven't even tentatively completed those evaluations yet, while the message laid out a handful of additional steps anticipated to take at least several months -- some involving outside experts, foreign authorities and requests for public comment.

Still, after more than a year of delays, persistent new engineering challenges and friction between senior FAA officials and Boeing's management, Sunday's message laid out the clearest path yet for resurrecting the MAX.

The crashes, which occurred less than five months apart in late 2018 and early 2019, kicked off debates in Congress and throughout the industry about FAA procedures and safeguards for approving the safety of new jetliner designs. The deaths also touched off a federal criminal investigation and prompted substantial changes in decades-old assumptions about how typical pilots interact with complex cockpit automation.

A Boeing spokesman said: "We continue to work diligently on safely returning the MAX to service."

FAA officials have consistently said they wouldn't move toward authorizing such test flights or taking other actions to recertify the MAX until all the agency's questions and concerns were answered satisfactorily. Leading up to test flights, Boeing has conducted more than 2,000 hours of flights to validate new software.

The world-wide slump in passengers resulting from the Covid-19 pandemic, though, has sharply reduced the airline industry's appetite for flying the troubled planes, and Boeing has dramatically scaled back its own production rates from previous levels.

Before making the decision Friday to schedule test pilots to vet various software fixes and changes to the jet's flight-control systems, the FAA formally signed off on a series of Boeing technical analyses and risk assessments that had taken months. Within days of the second crash, Boeing launched an effort to develop initial software revisions to an automated flight-control system called MCAS, which misfired, overpowered pilot commands and put both MAX jets into nosedives.

Under prodding from the FAA and international regulators, Boeing since then has revised several other features of the MAX's flight-control computers and associated hardware, including agreeing to relocate certain electrical wiring under the cabin to avoid hazardous short circuits.

The test flights, once planned for the summer of 2019, continued to be postponed as FAA and Boeing experts expanded their work to cover an array of new safety issues and previously unexamined computer shortcomings.

Even if the flight tests go well, the MAX faces more testing of the plane's handling by a group of international pilots, further analyses by pilot-training officials, verification by teams of outside safety experts and extensive maintenance work before the jetliners can be deemed ready to fly passengers.

In addition, Canadian and European regulators are pushing for other software changes that could be phased in over a year or more, once the planes return to service. Such separate safety tracts, according to many industry officials, threaten to erode the FAA's historic stature as the world's dominant air-safety regulator.

"There likely will be multiple changes attempted, many for nontechnical issues which will consume lots of time," said Ray Valeika, retired head of maintenance and engineering at Delta Air Lines Inc.

Over the months leading up to the decision to schedule the flights, industry and government officials projected that the FAA was likely to officially lift its order grounding the planes by early fall.

Airline officials have said they anticipate needing roughly two months after such a move to prepare aircraft for flight, phase them into their fleets and arrange for pilots to complete extra training in ground-based flight simulators expected to be required by the FAA. With some potentially important exceptions, international regulators are expected to follow the FAA's lead and clear the planes to fly within weeks of a final U.S. announcement.

Some 800 MAX planes are grounded, with roughly half of them in storage under Boeing's control because they were never delivered to customers.

With thousands of jetliners of various types sitting idle around the world because of the coronavirus pandemic, industry officials expect most airlines to move slowly to fit 737 MAX planes into truncated schedules.

Results of the test flights aren't likely to be released immediately, and a formal write-up could take weeks, according to industry and government officials. Later this summer, House and Senate leaders are expected to engage on provisions in rival bills intended to overhaul FAA certification of new aircraft designs.

FAA chief Steve Dickson, a former military and airline pilot, has said that before the agency's decision, he would personally test the revised software.

To boost passenger confidence in the redone flight controls, U.S. airline officials previously raised the possibility of conducting their own demonstration flights of MAX aircraft with executives and pilot-union leaders on board. The FAA has also considered strategies to explain the changes to regulators in other countries to ensure a coordinated return of the fleet.

Earlier this month, Boeing sent airline customers draft training materials, including more than a handful of revised checklists and rewritten emergency procedures, to pave the way for returning the MAX to service. At the time, the plane maker said it had worked closely with aviation authorities on the draft, noting that multiple regulators requested different changes to cockpit procedures.

Andrew Tangel contributed to this article.

Write to Andy Pasztor at andy.pasztor@wsj.com

(END) Dow Jones Newswires

June 28, 2020 17:56 ET (21:56 GMT)

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