Boeing whistleblower Sam Salehpour on Wednesday morning testified before the Senate Permanent Subcommittee on Investigations about safety issues with Boeing 737 jets.

Salehpour, a quality engineer at Boeing, told The New York Times that sections of the 787 Dreamliner fuselage were not connected properly and could break during flight after being worn down over time. His lawyer said he was sidelined, excluded and threatened after he raised concerns that “Boeing had begun taking shortcuts” to “reduce bottlenecks in the production of 787s.”

Watch his prepared remarks in the video above.