Ed Pierson, a former manager on the Boeing 737 Max production line who is about to testify before Congress, in Southworth, Wash., Dec. 7, 2019. Pierson, who called on Boeing to shut down the Max production line last year to no avail, believes production problems may have contributed to two deadly crashes. (Jovelle Tamayo/The New York Times)

Boeing 737 Max was ‘plagued
with production problems’

Whistleblower says he had warned the company with concerns four months before the first deadly crash