Former Top Boeing 737 MAX Officials Defend Design Process
Previous MAX program manager and chief engineer in closed-door congressional interviews stand by Boeing’s design of the plane
Two high-ranking executives who oversaw Boeing Co. BA 1.61% ’s development of the 737 MAX told House investigators the company’s design process wasn’t flawed despite two fatal crashes, a contrast to other company leaders’ concessions of past engineering errors.
The Chicago plane maker is approaching the final steps of getting its beleaguered MAX fleet returned to service. Lawmakers, safety experts and global regulators have previously identified technical and management lapses in the airplane’s development.
Transcripts of closed-door interviews in May with Keith Leverkuhn and Michael Teal, who directly managed MAX development through the aircraft’s 2017 debut, are part of a final congressional report slated to be released this coming week detailing a series of company and government missteps during and after certification of the MAX.
Their stance shows that nearly two years after the first fatal crash, there are differing views inside Boeing and a continuing debate across parts of the industry about the significance of pilot mistakes versus Boeing design flaws as factors in the MAX crashes.
“The cause of the accidents is a very complex thing, that there are multiple things that occurred,” Mr. Teal said at one point in his interview.
Misfires of the cockpit system, called MCAS, overpowered pilots on a pair of MAX jets less than five months apart, causing fatal nosedives and prompting a global grounding of the fleet that has remained in effect since March 2019.
The statements to the staff of the U.S. House Transportation Committee, reviewed by The Wall Street Journal, reflect a vigorous defense of Boeing’s engineering practices and safeguards. In the wake of 346 deaths, billions of dollars in company losses and the biggest blow to the plane maker’s reputation in its 104-year history, the two executives didn’t concede any procedural mistakes during the plane’s six-year development process.
Mr. Leverkuhn, who served as the MAX program manager from 2013 to 2018 before moving to what he said was a higher-salaried role overseeing jet propulsion systems, at one point in the interview said, in response to a question, that he would consider the plane’s development a success, according to the transcript. Like Mr. Teal, he said the MAX’s creation followed standard Boeing protocol.
“I do challenge the suggestion that the development was a failure,” Mr. Leverkuhn said, during sometimes-contentious exchanges with investigators.
Mr. Leverkuhn, who stressed the MAX design process was the same as for all other Boeing jets, at another point in the interview said: “I believe the process was correct and appropriate.”
Last October, then-Chief Executive Dennis Muilenburgtold lawmakers in public testimony he was responsible and accountable for the MAX debacle, adding: “We’ve made mistakes and we got some things wrong.” The company’s board later pushed him out.
According to the transcripts, Messrs. Teal and Leverkuhn told investigators they signed off on MCAS without fully understanding how it worked; they also said the design of the flight-control feature met company and federal certification and safety requirements. Mr. Teal said he signed off on high-level configuration of the aircraft and its systems, leaving lower-level engineers to work out MCAS details. “That’s typically how flight-control laws are worked with,” he said.
The interviews marked the two men’s first public statements since before the initial MAX crash of a Lion Air jet in Indonesia in October 2018. A MAX operated by Ethiopian Airlines crashed in March 2019.
In a statement to The Wall Street Journal, Boeing said Messrs. Leverkuhn and Teal supervised hundreds of engineers and, given their broad responsibilities, “were not, and could not have been, involved in every design decision” on the aircraft.
Boeing also reiterated it has taken steps to improve its internal procedures. “We have made important changes to our certification process, and to our company,” Boeing added, “as a result of what we have learned from our internal assessments and the many independent reviews.”
Boeing declined to make the executives available to comment.
Mr. Leverkuhn retired this year as he had long planned, a Boeing spokesman said.
Mr. Teal, who as the MAX’s chief engineer personally signed off on MCAS and served as Mr. Leverkuhn’s deputy, told the House panel’s investigators Boeing’s team designed the MAX following longstanding industry assumptions and complied with established company practices.
He is now the top engineer in charge of developing Boeing’s 777X, the company’s next new jetliner.
Mr. Teal told investigators he approved MCAS without knowing that a malfunction of a single sensor could trigger the system to repeatedly push down a plane’s nose and possibly lead to a crash if pilots fail to respond appropriately within a matter of seconds. “I don’t believe it was a mistake,” he said, based on what engineers knew when they were developing the plane years ago. He said he relied on experts in various engineering disciplines to determine the system’s design and safety.
After MCAS was flagged by test pilots in 2016 as a high-priority answer to a separate handling deficiency that could jeopardize Federal Aviation Administration approval, Mr. Teal recalled, he sent several other Boeing pilots to check out the system but never learned what changes engineers ultimately devised to solve the problem.
“The team followed the process that we use to design, you know, flight control systems and went through the process of working with the pilots as well as the stability and control” engineers, Mr. Teal said.
Since the crashes, Boeing, other plane makers, regulators and accident investigators world-wide have significantly revised an industrywide assumption about how quickly average pilots can be expected to respond to certain emergencies. In hindsight, both executives said that assumption was faulty.
Boeing has since jettisoned the long-held industry assumption that pilots would respond appropriately to cockpit emergencies within four seconds.
The overall design effort was correct and appropriate, Mr. Leverkuhn said, “but that assumption underpinning that process was proven to be incorrect.”
According to the transcripts, they said Boeing was committed to applying lessons learned from the MAX’s travails to enhance safety and improve internal controls. Mr. Teal, now the 777X’s current top engineer, said the revised pilot assumption was “a learning that we are now putting forth on the new aircraft.”
Boeing has added numerous safeguards to MCAS since the crashes. Among other changes, the cockpit system now relies on two sensors to verify accurate data, instead of just one, and it will just push the nose down once.
Boeing’s statement. also said the MAX’s development “complied with the FAA’s certification requirements at the time.” The company said it has bolstered safety by restructuring “to give engineers a stronger voice and a more direct line to share concerns with top management.”
Mr. Teal dismissed the notion that the company was motivated by financial reasons to avoid extra mandated simulator training and instead emphasized the safety advantages of developing the aircraft with handling characteristics identical to earlier 737 models. “It’s not about the dollars and cents,” he told the House investigators. “It’s about the safety aspect.”