The infamous Boeing 737 Max airplane hasn't quite made it out of the woods yet.
Last month, the U.S. Federal Aviation Administration (FAA) cleared the 737 Max to fly again in the U.S. Last Friday, however, U.S. Senate investigators said that the FAA and Boeing manipulated the airplane's test flights during its recertification process.
The planes were grounded for nearly two years following two fatal crashes in 2018 and 2019 that killed hundreds of passengers and crew.
The U.S. Senate investigators stated that the FAA and Boeing "inappropriately coached" flight pilots during recertification test flights, and that some tests were even carried out on simulators that weren't set to re-create the crash scenarios.
Moreover, the investigators claim the FAA and Boeing are "attempting to cover up important information that may have contributed to the 737 MAX tragedies."
Boeing officially responded stating it takes "seriously the Committee’s findings and will continue to review the report in full."
"Boeing is committed to improving aviation safety, strengthening our safety culture, and rebuilding trust with our customers, regulators, and the flying public," the company's statement read.
The FAA, on the other hand, is confident its series of tests have been thorough.
The 102-page-long report, which was released on Friday, was put together by the Senate Committee on Commerce, Science, and Transportation, and is built upon 50 whistleblowers' information, FAA staff interviews, and over 15,000 pages of documents.
Boeing has previously been poked and proded regarding its MAX 737's and has dutifully answered. This is one of the first time the FAA comes under such strong scrutiny, opening up a pandora's box of worries about how the regulator operates.
"Our findings are troubling," Sen. Roger Wicker, who chairs the committee, said in a statement.
"The report details a number of significant examples of lapses in aviation safety oversight and failed leadership in the FAA. It is clear that the agency requires consistent oversight to ensure their work to protect the flying public is executed fully and correctly."
What the report broadly points out is that the testing process to re-integrate the Boeing Max 737 into business was riddled with problems. According to the document, some FAA investigators left testing processes early, while other tests were carried out on simulators not equipped to re-play the disastrous problems the airplanes faced in 2018 and 2019.
One stand-out point in the report cited a whistleblower who claimed Boeing officials told test pilots to use a specific control directly before an exercise.
These are worrying statements, especially given some airlines have already sent Max 737's back into the skies. These include Brazil's Gol Airlines, which started flying the planes earlier this month. Next up is American Airlines, which is set to fly its first 737 Max flights in the U.S. on 29 December.