John Barnett had worked for Boeing for 32 years, until his retirement in 2017.
In the days before his death, he had been giving evidence in a whistleblower lawsuit against the company.
Boeing said it was saddened to hear of Mr Barnett’s passing. The Charleston County coroner confirmed his death to the BBC on Monday.
It said the 62-year-old had died from a “self-inflicted” wound on 9 March and police were investigating.
If you’re going to fly Boeing at all, what is the point in avoiding the 737-max?
Because most older Boeing models are actually robust aircraft & when the maintenance is in the hand of a capable airline, there’s nothing wrong with them from the perspective of safety. But as Boeing continues to fuck this up, and murder whistleblowers - I doubt there will be Boeing airplanes left to safely board in the future.