Congressman Peter DeFazio’s sweeping investigation into Boeing and the safety of its 737 Max has painted a devastating portrait of the world’s largest airplane manufacturer as well as the regulatory agency created to oversee the industry.

The U.S. House Transportation and Infrastructure committee, which DeFazio leads, has found evidence that Boeing designed a navigation system into the 737 Max that executives and engineers knew was flawed and tended to force the planes into nosedives. The problems contributed to two crashes that killed nearly 350 passengers and grounded the 737 Max indefinitely.

In a Friday interview, DeFazio took a hard line. “They developed a fatal system that was extremely difficult for the pilot to override,” he said.

Another bombshell hit Thursday when DeFazio and Rick Larsen, who co-chairs the committee, alerted the Federal Aviation Administration that it had found two new “serious, potentially catastrophic safety concerns” with the Boeing aircraft.

It is the largest, most wide-ranging investigation the committee has undertaken in DeFazio’s 33 years. They’re not only pursuing Boeing, but also the FAA, which DeFazio claims has not done its job policing the industry.

In the case of one of the new problems — a rudder cable alleged to have inadequate protection from engine failure — DeFazio claims that FAA leaders overruled their own technical specialists who had alerted superiors to the problems. Instead, the agency sided with Boeing, which had objected to the agency’s original findings.

DeFazio’s hearings have been overshadowed somewhat by the impeachment fever that has gripped the Capitol. But the media came out in force on Oct. 29 to watch the testimony of Boeing CEO Dennis Muilenburg.

“My company and I are responsible for our airplanes,” Muilenburg told the committee. “We know that there are things we need to improve. We are doing that. I am accountable and my company is accountable. The flying public deserves a safe airplane.”

Muilenburg apologized to family members of the crash victims who attended the hearing.

At the heart of Boeing’s problems is the Maneuvering Characteristics Augmentation System, which the company opted to include in the 737 Max. The system has been blamed in both of the crashes.

The software was intended to make the Max fly like previous 737s. But the Max has larger engines than prior generations, forcing engineers to reposition them on the wings.

That repositioning changed how the jet performed.

But the system also tended to push planes’ noses down, making it difficult for pilots to retake control.

DeFazio contends that Boeing had a financial incentive to downplay concerns about the new system. It was locked in a difficult battle with Airbus, its European archrival, which had introduced a competitive model. One of the strengths of the Airbus plane was that experienced pilots didn’t need to be trained on the new craft.

Boeing felt pressure to make the 737 Max similarly user-friendly.

In the end, Boeing installed the system, but didn’t tell its customers. Evidence gathered by the committee indicates the company scrubbed any reference to the system from user manuals and warnings from its own test pilots went unheeded, DeFazio said.

The fleet of 737 maxes were grounded in March 2019.

Boeing said the Max disaster has cost the company $9 billion, which includes the $5 billion it expects to pay in settlements with survivors of the 346 dead.

DeFazio speculated that the lure of big money contributed to Boeing’s bad decisions. He noted that even after the first 737 Max crash, Muilenburg got an enormous $13.1 million bonus.

It’s becoming more difficult to get people to come forward.

The Department of Justice launched its own criminal investigation of the crashes. Some potential witnesses are hiring criminal defense lawyers, who are forbidding them from testifying.

But DeFazio vows the committee will continue to dig for evidence until members are satisfied they have completed their task.

“Wall Street, market forces, have a way of influencing the decisions of the best companies in the worst way, endangering the public and jeopardizing the good work of thousands of line workers” he said. “I hope that this is not the story that will be written about this long-admired company.”