Numerous Boeing employees raised safety concerns about the 737 Max months and years before the two deadly crashes that led to the jet’s grounding, according to documents released by a House panel Wednesday.
A document revealed by the House Transportation Committee shows that in December 2015, a Boeing engineer expressed concern about the safety of the anti-stall system that played a role in the two crashes.
“Are we vulnerable to single [angle of attack] sensor failures with the MCAS implementation or is there some checking that’s ours,” the engineer wrote in an email to other Boeing employees.
The automated system, known as the Maneuvering Characteristics Augmentation System, or MCAS, was the link between two fatal crashes of Lion Air and Ethiopian Airlines flights that killed a total of 346 passengers on board.
The system fed the 737 Max’s computer system inaccurate data on its angle of attack, leading to a struggle between the system and the pilot.
The Boeing engineer sent the email nearly two years before federal regulators certified the jet and obtained as part of the committee’s investigation into the plane’s failures.
Another document from June 2018 showed Boeing employees warned if pilots took more than 10 seconds to respond when the anti-stall system was activated, it could be “catastrophic.”
In a third document, an email sent four months before the Lion Air flight crashed off the coast of Indonesia and read by Rep. Albio Sires, D-New Jersey, the former general manager of the 737 program warned in June 2018 the workforce involved in final assembly of the 737 Max was “exhausted” from working at a high pace for a prolonged period and could be susceptible to making mistakes.
The senior manager, who had 30 years of aviation experience, also said “schedule pressure (combined with fatigue) is creating a culture where employees are either deliberately or unconsciously circumventing established processes.”
“Frankly right now all my internal warning bells are going off,” the employee wrote, according to Sires. “And for the first time in my life, I’m sorry to say that I’m hesitant about putting my family on a Boeing airplane.”
The Boeing manager recommended shutting down production of the 737 Max, Sires said.
“Nothing we do is so important that it is worth hurting someone,” the senior manager added.
[Read more: Boeing expects 737 Max to be flying again by end of year]
Boeing CEO Dennis Muilenburg told Sires he was aware of the concerns that were raised by the employee, who also wrote to Muilenburg and spoke with Boeing’s assistant general counsel following the Lion Air crash.
The Boeing chief told lawmakers after the employee sent the email, the company implemented additional quality checkpoints in the production line and identified areas where the senior manager’s concerns had been addressed.
“We take those input seriously, we evaluated them, we responded, and we’re continuing to take action,” Muilenburg said.
Boeing’s fleet of 737 Max planes has been grounded since mid-March, and Boeing completed a software fix for the anti-stall system in May. It also implemented additional safety enhancements. The grounding has caused U.S. carriers to extend flight cancellations into 2020 and has cost Boeing billions of dollars.
Regulators, meanwhile, have yet to give the green light for the 737 Max to return to commercial service, and Muilenburg told the Senate Commerce Committee on Tuesday the plane will fly when “everyone is convinced it’s safe.”
