Boeing officials 'inappropriately coached' government test pilots during a review of the 737 Max after the model was involved in two fatal crashes, according to Senate investigators

• Boeing officials inappropriately influenced government test pilots as they were testing the company's 737 Max plane before recertifying it for flight, Senate investigators said in a report Friday.
• The investigators said the FAA failed to provide proper oversight of Boeing and Southwest Airlines, potentially putting passengers at risk as a result.
• In a statement, the FAA expressed confidence that the issues which led to the two fatal crashes have been resolved.

Boeing officials "inappropriately coached" government pilots during a simulator test to ensure that the company's 737 Max plane was safe to fly again, after two deadly crashes involving the model killed 346 people, Senate investigators said in a report Friday.

Some pilots of the Federal Aviation Administration, who went through the simulation, were prompted by Boeing to get ready to use the right controls, according to the report published by the Senate Committee on Commerce, Science, and Transportation, which received information from 57 whistleblowers.

The accusations included in the 100-page report extend far beyond issues with the testing process. The FAA has a culture of retaliation, the investigators said, and its leadership allowed Southwest Airlines to operate aircraft that may have been unsafe to fly.

"The FAA continues to retaliate against whistleblowers instead of welcoming their disclosures in the interest of safety," the report said.

The committee originally launched the investigation after two fatal crashes, in 2018 and 2019, involving Boeing 737 Max planes. They later expanded the scope of the probe as whistleblowers and documents raised concerns about the FAA, which is responsible for regulating the industry.

The FAA cleared Boeing's 737 Max again last month, and a number of airlines have since announced that they will reintroduce the planes to their fleets.

Read more: The FAA has cleared Boeing's 737 Max to fly passengers again - here's when and where each US airline will be flying it

The FAA said in a statement to Reuters Friday that it's "carefully reviewing the document, which the committee acknowledges contains a number of unsubstantiated allegations," adding that it's "confident that the safety issues that played a role in the tragic (737 MAX) accidents involving Lion Air Flight 610 and Ethiopian Airlines Flight 302 have been addressed."

In a public statement, Boeing said that it's "committed to improving aviation safety, strengthening our safety culture, and rebuilding trust with our customers, regulators, and the flying public."

"We take seriously the Committee's findings and will continue to review the report in full," the statement continued. "We have learned many hard lessons from the Lion Air Flight 610 and Ethiopian Flight 302 accidents, and we will never forget the lives lost on board. "

'FAA and Boeing were attempting to cover up important information'

Boeing's missteps leading up to the fatal crashes are well documented, but few probes have focused on the FAA, until now.

The new report alleges that the FAA failed to provide adequate oversight of flight safety during the recertification process. In some instances, Boeing officials "inappropriately coached" pilots during the test to get a desireable outcome, the Committee said. Some FAA investigators also left tests early or carried out tests using simulations that didn't have the relevant software, the investigation found, as reported by The Verge.

"FAA and Boeing were attempting to cover up important information that may have contributed to the 737 MAX tragedies," the report said.

Southwest Airlines may have operated planes that were unsafe, the investigators found

The Committee also found issues with FAA's oversight of Southwest Airlines, more than a decade after the agency fined the carrier, stating at the time that Southwest failed to properly inspect its aircraft.

Between 2013 and 2017, Southwest purchased planes from foreign manufacturers that were cleared to fly based on "deficient information," the investigators said in the report. Whistleblowers alerted FAA to this but the agency didn't ground the planes.

"The FAA repeatedly permitted Southwest Airlines to continue operating dozens of aircraft in an unknown airworthiness condition for several years," the investigators wrote in the report. "These flights put millions of passengers at potential risk."

In a statement to The Verge, Southwest Airlines said "we are aware of the Committee report and have utilized many of these past references to improve our practices and oversight."

"All applicable aircraft underwent visual inspections, and Southwest completed physical inspections, from nose to tail, on each of the pre-owned aircraft by January 2020 - fully satisfying FAA requests," the statement continued. "Our actions did not stem from any suspected Safety concerns with the aircraft but were an effort to reconcile and validate records and previous repairs."

The company plans to resume 737 Max service in the first three months of next year, per The Verge.