WASHINGTON, D.C. (MyBellinghamNow.com) – Boeing is pushing back after a whistleblower sparked more criticism over its safety protocols.

Two Boeing engineering executives went into detail during a media briefing Monday to describe how panels are fitted together, particularly on the 787 Dreamliner.

It comes after Boeing quality engineer Sam Salehpour publicly detailed his concerns over shortcuts he claims Boeing took in its assembly process. Salehpour alleged that excessive force was used to fit panels together on the 787-assembly line, which raised the risk of cracking that could cause the panels to break apart. He added that after he raised safety concerns over the 787, Boeing transferred him to work on its older 777 aircraft.

Salehpour told the Seattle Times that he saw workers jumping on fuselage panels to get them in alignment – a claim that Boeing disputes. The New York Times reports that the Federal Aviation Administration (FAA) is investigating Salehpour’s claims, while Boeing says it is “fully confident” in both planes.

Salehpour is scheduled to testify before Congress on Wednesday, April 17.