Inside the fraternity of Boeing pilots, it was an eyebrow-raising moment that later, after the uneventful flight landed to cheers, led to some teasing of the crack duo, Ed Wilson and Craig Bomben, for missing one of the steps in the preflight checklist.

More than an ironic footnote in the Max saga, the incident is a window into the prideful culture that led to two crashes and 346 deaths, a worldwide grounding of Boeing’s marquee jet, and unprecedented scrutiny of the storied planemaker’s processes. Aviation authorities have weighed in on how Boeing engineers failed to anticipate pilots’ reactions to a cacophony of alerts from misfiring flight control software, how managers pressured engineers to speed the completion of their designs, and how an acquiescent Federal Aviation Administration missed the deadly risk from software changes made late in testing.

But the most fundamental breakdown at Boeing may have been a lack of appreciation of how humans respond under stress—both in the machine it was designing and in its own organization. On aircraft like the Boeing 777, a cadre of pilots had worked closely with engineers to solve problems. By the time the Max entered development, Boeing was pushing hard to turn the unglamorous but all-important business of customer training into a profit center of its own. Many pilots were distracted by a dispute with Boeing over the hiring of outside contractors. They contended the quality of training was slipping.

Commercial Aircraft Produced by Boeing

In 2013, a year after a vote that more than doubled the number of unionized pilots, the company announced that it was moving its Seattle-area flight simulators to Miami. There and in cities such as Singapore and London, amid an historic wave of orders, it relied on hired help known as “purchased service pilots,” or PSPs. Boeing’s longtime trainers had another abbreviation for them: DBCs, or “dirtbag contractors.”

In practice, according to interviews with more than a dozen pilots and engineers who participated in the Max’s development, the turmoil left the aircraft’s cockpit designers with a lack of input from the instructors who regularly saw how the typical airline pilot responded to unusual situations. Even among the pilots, there were communications breakdowns, partly caused by disagreements over unionization. At times conversations were civil but terse.

Boeing’s fight with the pilots came at the same time as layoffs among the engineers and was part of a drive, these people say, to lessen the clout of Seattle-area unions. Company reassignments placed thousands of miles between designers honing flight-deck concepts in Seattle, trainers working with airline pilots in Miami, and a team in California that provides day-to-day support of airplanes in the field. “The driving factor was monetary,” says Mike Coker, Boeing’s former chief training pilot. “Those relationships between the various professional organizations that for decades resulted in a good product, an improved product—they weren’t taken into consideration as much as the bottom line.”

In an email, a Boeing spokesman said that “training requirements are mandated by global regulators and implemented by airline customers. Boeing continues to invest in dedicated capability and resources to assist our customers in training.” He added that Boeing has 41 full flight simulators in nine locations across four continents.

Three former senior Boeing executives, however, say privately that they regret the profit-driven imperatives imposed on the training process and see it as critical to understanding how a company renowned for meticulous engineering missed the mark so badly with the Max. For century-old Boeing, whose name is nearly synonymous with flight, the crisis isn’t only a human tragedy but a deep embarrassment and a financial disaster costing billions of dollars. And it’s made Chief Executive Officer Dennis Muilenburg, who’s taken heat from congressional leaders and crash victims’ families in tense hearings, the technocratic face of a deadly corporate blunder.

The financial pressure is only mounting after the FAA pushed back on the timeline to get the Max back in the air, prompting Boeing to announce on Dec. 16 that it will suspend production of its biggest cash generator starting in January. The company already has almost 400 newly built aircraft languishing in storage because of a global flying ban that began nine months ago. “This pause may indicate that the reentry into service of the 737 Max is not just around the corner, as bullish investors may have been anticipating,” Ron Epstein, an analyst at Bank of America Corp., wrote in a note to clients.

It wasn’t supposed to happen this way. In late 2010, Airbus SE surprised Boeing by offering airlines an update of the 737’s chief competitor, the A320. The new version would have more powerful engines to save on fuel but few other changes, allowing customers to keep down the costs of training pilots to fly it. Boeing responded by announcing a similar plan to modernize the 737, a plane designed in the 1960s that had already been updated twice.

After a design meeting, Pete Parsons, an executive in the commercial airplanes unit with a mouthful of a title (director of program management best practices and program management functional excellence), declared the plans “the best I’ve seen.” He told Boeing’s internal newsletter that he was especially impressed with the “clear communications” and “high level of collaboration.” As Jim Albaugh, then Boeing’s chief of commercial airplanes, laid out the marching orders for the Max in the December 2011 newsletter: “We’re going to make this the simplest re-engine possible. We’re only going to touch the part of the airplane impacted by the engine and a couple of other improvements.”

The industry was in the midst of the greatest boom of the jet age, as the combination of millions of newly mobile middle-class travelers in Asia and low interest rates prompted airlines to order planes at a frantic pace. In the past decade, carriers have taken delivery of single-aisle jets worth $442.2 billion—36% of all such planes manufactured in the previous half-century, according to the aerospace consulting firm Teal Group. It stretched their ability to train and recruit pilots.

Boeing had long prided itself on the quality of its training, dating to the College of Jet Knowledge it established during the development of the first successful commercial jet transport, the 707 in the 1950s. That plane was put through its paces by the most famous of Boeing’s test pilots, Alvin “Tex” Johnston, who wore specially made boots for each new model and gleefully courted risk. In 1955 he stunned Boeing executives by executing a barrel roll in a 707 prototype over a crowd of onlookers at a Seattle festival.

Decades later, the Boeing pilots are a tamer bunch, though some are said to still be members of the Quiet Birdmen, an aviators’ club dating to World War I. They’re also more specialized. In addition to the Boeing pilots who test new models, there are others who train airline crews or write manuals.

But the company has been trying for years to capture more of the commercial pilot training market, forming a joint venture with a Warren Buffett-owned company in 1997 that ended in 2002 and, in 2003, creating a subsidiary known as Alteon, renamed Boeing Training & Flight Services in 2009. The moves prompted instructor pilots to form a union they called the Lazy B Pilots Association, rankling management and some of the test pilots, who weren’t unionized.

The training unit introduced a points-based system for its airline customers akin to the airlines’ frequent-flyer programs. Instead of providing expensive simulator time—which can cost hundreds of dollars per hour—for a set number of crews as it previously had, Boeing offered points that could be used for a combination of training for pilots, maintenance technicians, or flight attendants. “It’s like swapping fries for boiled potatoes,” Alteon’s chief, Sherry Carbary, told the trade publication FlightGlobal in 2007.

Carbary, now president of Boeing China, warned of a training reckoning for the industry amid the wave of new pilots and said it demanded a single-minded response. “We must, as an industry, find a way to lower the costs,” she said at a convention in Orlando in 2007.

The effort didn’t sit well with some of Boeing’s instructors. “We felt like shortcuts were being taken and that the quality of training was being sacrificed,” says Charlie Clayton, a former Boeing instructor. The airlines, too, had “a vested interest in getting pilots out and flying as quickly as they can, as cheaply as they can.”

Tensions boiled over with a plan to use contractors, often retired airline pilots, to fly with crews for initial training. In 2012 the trainers and manual writers voted 4 to 1 to join Boeing’s engineers’ union, the Society of Professional Engineering Employees in Aerospace. Managers made it known that the vote wouldn’t help their chances at promotion, four former workers say. The next year, in the middle of negotiations for a new contract for several dozen pilots, managers delivered a bombshell: They were moving the simulators to Miami, where Boeing had a training center that had been part of the by-then-shuttered joint venture with the Buffett company. Boeing said it was what customers wanted.

As the Max was in development, Boeing squeezed the union in other ways, too, shipping more than 3,900 jobs out of the Seattle area. Among the first to leave Boeing as job insecurity grew were experts in so-called human factors, scientists and psychologists steeped in research of how people interact with machines. Without their input, says Rick Ludtke, a former cockpit designer, “it was easier for the program leaders to drive their wishes into the design teams. They just didn’t have people who understood that you need to say no.”

The beefed-up Miami center wasn’t popular with all customers, says Coker, the former chief training pilot. Some objected to instruction from contractors instead of full-fledged Boeing pilots. Other former instructors say the Miami building was shopworn.

But there was a more worrisome consequence: The move disrupted the informal relationships among engineers and trainers in the Seattle area who could easily convene at one of the simulators to talk over designs. (Another type of simulator known as an E-cab did remain in Seattle, employees say, but it was harder to schedule because of the increased demand for it.) “When the simulators were downstairs, there was an extreme amount of crosstalk,” Coker says. “We could do a walk-through or a rehearsal of a proposed procedure and see where the flaws were—much harder when you have to go to Miami or tell somebody over the phone.”

It was from a hotel room in Miami that former Boeing pilot Mark Forkner—one of the manual-writing pilots—sent frustrated instant messages in November 2016 about a Max simulator that wasn’t working, according to a former colleague. When congressional investigators released those messages this October, they caused an outcry because they seemed to suggest Boeing knew of issues long before the Max was flying. What they may show instead is a lousy information loop at the company.

Early in 2016 test pilots and engineers had expanded the authority of a software system that had the ability to point the Max’s nose down. It was meant to address a limited stall condition most pilots would never see. But Forkner and others working on the simulator hadn’t been alerted about the change or that FAA staff had already observed it activate during test flights. “Why are we just now hearing about this?” Forkner wrote. His lawyer didn’t respond to emailed questions.

Problems with the system have been tied to a single point of failure—a vane that measures the angle of the plane’s nose against the oncoming wind. When it malfunctions, the measure trips a bewildering array of cockpit warnings including a thumping alert known as a stick-shaker that indicates a plane is in danger of stalling.

Boeing never tested how pilots would respond to such a failure, which later occurred in the accidents. “When they look back, the failure to adequately test this in the sim was Problem One,” says Chris Hart, former chairman of the U.S. National Transportation Safety Board, who led a panel of aviation authorities examining the Max’s shortcomings. “Fragmentation played a big role in it, the failure to communicate.”

Boeing has vowed a massive pilot training initiative, part of a broader effort to reinforce safety. Pilots say it’s recently advertised jobs for more in-house trainers. Muilenburg says Boeing has already begun rethinking the design of its flight decks to ensure human responses are adequately considered.

But no reexamination can reverse the human toll suffered before the Max’s initial design and training flaws were discovered. Boeing delivered the first Max jets to a Lion Air subsidiary in mid-2017. Just 15 months later, the carrier’s pilots on successive flights were forced to troubleshoot the design problem that Boeing had missed.

Taking the Max through a preflight checklist in Jakarta in October 2018, Lion Air Captain Bhavye Suneja typified the new generation of pilots across Asia. At 31, he’d amassed 6,000 hours of flying time, mostly on the 737. He didn’t know that one of the tiny vanes that measures the angle of the plane’s nose was broken and would set off a terrifying fight for control of the plane. On a previous flight of the same aircraft, a pilot in the jump seat had suggested flipping two switches to cut power to the stabilizer pushing the nose down but had left no mention of it in their logbooks. So Suneja lacked a crucial piece of information that might have avoided tragedy. As a result, horrified crewmen watched from an oil platform as the almost brand-new $120 million plane plunged into the Java Sea, killing all 189 aboard.

Days later, Boeing issued a checklist reminding pilots they can flip the switches to disable the stabilizer. It also began work on a software update to keep a broken vane from triggering the system.

In March, Ethiopian Airlines Flight 302 took off from Addis Ababa and dropped out of the sky six minutes later. Captain Yared Getachew, 29, and his co-pilot quickly recognized that the rogue software behind the Lion Air crash had kicked in. They hit the cutout switches, but amid the confusion left the jet’s engines gunning at full takeoff throttle, making it difficult to control. They flipped the switches back on, and the plane dove. An additional 157 people were dead. “We cry every day,” says Michael Stumo, father of Samya Stumo, 24, one of the victims.