Hundreds of people could lose their lives if Boeing fails to address quality issues, a whistleblower warned the US Congress, Report informs via The Guardian.

Sam Salehpour, an engineer at the planemaker, told a high-profile hearing on Capitol Hill that he feared “physical violence” after going public with his concerns. There is “no safety culture” at Boeing, he claimed, alleging that employees who raise the alarm are “ignored, marginalized, threatened, sidelined and worse”.

Salehpour, who has worked at Boeing for more than a decade, said he had identified an issue with gaps between key sections of the 787 Dreamliner that has affected “more than 1,000” jets in service, warning it was “likely to cause premature fatigue failure over time in two major airplane joints”.

Another witness at the hearing, Ed Pierson, a former Boeing engineer who now leads the Foundation for Aviation Safety, alleged a “criminal cover-up” in the wake of the cabin panel blowout that sparked the manufacturing giant’s latest safety crisis.

The incident in January raised fresh questions about the production of Boeing’s bestselling commercial jet, the 737 Max. But it is now facing intense scrutiny across its fleet.

The Federal Aviation Administration is investigating allegations by Salehpour that Boeing took shortcuts to reduce production bottlenecks while making the 787. He also raised issues about the production of the 777, another wide-body jet.

Before Wednesday’s hearing, Salehpour called on Boeing to ground all 787 jets for inspection. He has claimed sections of the fuselage could break apart after thousands of trips.

In written testimony, Salehpour said that he contacted Richard Blumenthal, a US senator, “because I genuinely believe that the safety problems I have observed at Boeing, if not addressed, could result in a catastrophic failure of a commercial airplane that would lead to the loss of hundreds of lives”.

Boeing said it had “taken important steps to foster a safety culture” since 2020, but added in a statement: “We know we have more work to do and we are taking action across our company.”

In recent days, the company has insisted the 787 and 777 are safe, describing Salehpour’s allegations about the Dreamliner as “inaccurate”. At a briefing this week, executives described how a rigorous program of tests and inspections had left the firm confident of the jets’ durability.

Separately, as the National Transportation Safety Board (NTSB) investigates January’s cabin blowout, Pierson noted the watchdog had “reiterated to Congress that Boeing has said there are no records” documenting work associated with the removal of a door from the jet before the incident, which forced the emergency landing of an Alaska Airlines flight.

“In my opinion, this is a criminal cover-up,” Pierson said. “Records do exist documenting in detail the hectic work done on the Alaska Airlines airplane, and Boeing’s corporate leaders know it, too … I know this Alaska airplane documentation exists because I personally passed it to the FBI.”

Pierson told senators that the records were supplied to him by “an internal whistleblower”.

Boeing declined to comment on Pierson’s allegation, referring questions to the NTSB. In a statement, the NTSB said it had not received documents detailing work on the Alaska jet’s door plug “from Boeing or any other entity”, urging anyone with relevant information to contact its investigators. Alaska was also contacted for comment.

Salehpour says he faced retaliation as he repeatedly sought to raise the flag inside Boeing over three years. “I was ignored,” he told the Senate’s permanent subcommittee on investigations. “I was told not to create delays. I was said, frankly, to shut up.”

On one occasion when he tried to discuss problems, Salehpour alleged his supervisor said to him: “I would have killed anyone who said what you said if it was from some other group, I would tear them apart.”

Boeing has insisted that retaliation was “strictly prohibited” at the company.

After scrambling to reassure regulators, airlines and passengers in the wake of January’s blowout, Dave Calhoun, Boeing’s chief executive, and Larry Kellner, chair of its board, last month announced plans to resign.

“I believe that Boeing can do better and that the public’s trust in Boeing can be restored,” Salehpour said in his testimony. “I hope that this committee will hold Boeing accountable and demand an end to a business culture that prioritizes profit and speed over safety.”