The statement was posted online as a result of Friday's bombshell, when instant messages between senior Boeing pilots came to light. The messages recount an experience that one pilot had during a simulator trial, where he noted that the MCAS software handling performance was "egregious", according to Bloomberg. 

The MCAS system played a direct role in two fatal crashes that killed 346 people. 

Boeing said in its statement on Sunday: "We understand and regret the concern caused by the release of the instant messages. It is unfortunate that this document, which was provided early this year to government investigators, could not be released in a manner that would have allowed for meaningful explanation."

It continued: "Boeing engaged in an extensive process with the FAA to determine pilot training requirements for the 737 MAX 8. This process was a complex, multiyear effort that involved a large number of individuals at both Boeing and the FAA. This effort itself was just a part of a much larger regulatory process for the design, development and certification of the 737 MAX 8."