Boeing is facing newly revealed whistleblower claims that its 787 Dreamliner planes have structural failings that could eventually cause them to break apart, adding to the unprecedented crisis facing the aviation giant.
The Federal Aviation Administration is investigating claims made by Boeing engineer Sam Salehpour, The New York Times reported Tuesday.
In a lengthy response, Boeing strongly disputed the claims and said it was "fully confident" in the 787.
But the new allegations come at a bruising time for the Virginia-based company, two weeks after CEO Dave Calhoun and other senior executives announced they would step down following a series of damaging stories about the safety of its jets.
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Calhoun said a door plug blowout on a Boeing 737 Max plane flown by Alaska Airlines in January was a "watershed moment for Boeing" — and now the company he leads until the end of the year is again forced to defend its safety record and protocols.
Salehpour, who has worked at Boeing for more than 10 years and has sent his allegations to the FAA, said that a change to the construction process had introduced shortcuts that caused parts of the plane's fuselage to be improperly fastened together. These parts could, he warned, fall apart after thousands of flights.
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He told The New York Times that the plane's fuselage comes in several large pieces from different manufacturers that are fastened together on an assembly line.
In 2019, the Times spoke to other Boeing whistleblowers at the plant in Charleston, South Carolina, where the 787 is made. They alleged that workers were pressured to work quickly on the planes and that concerns were ignored.
One of those whistleblowers — John Barnett, a former Boeing quality inspector who raised safety concerns at the Charleston plant — was found dead in the city in March while conducting legal action against the company. A legal expert has said his lawsuit could continue posthumously.
It appears that Salehpour had previously sent his concerns to the Senate Homeland Security and Governmental Affairs Committee.
Sen. Richard Blumenthal, D-Conn., who chairs the panel's investigations subcommittee, said Tuesday night that he received a whistleblower's allegations earlier this year and had invited Salehpour to speak at a hearing on "Boeing's broken safety culture" next week.
Blumenthal and committee ranking member Ron Johnson, R-Wisc., wrote to Boeing and the FAA in March to say they had received whistleblower claims from a Boeing engineer about "potentially catastrophic safety risks" with the 787, without naming Salehpour.
Launched after a series of delays in 2011, the 787 was the first commercial jet with a main structure mostly made from composite materials, primarily carbon-fiber reinforced plastic, which are lighter than metals such as aluminum.
Boeing said Salehpour's allegations were "inaccurate" and contrary to the findings of comprehensive testing that had found the 787 could operate safely before needing "conservative maintenance routines." A single plane could be in service for 40 to 50 years, the company said.
On the specific allegation about the possibility of newer materials failing under repeated stress of flight, the company said: "Another benefit of the 787’s composite structure is the material does not fatigue or corrode like traditional metals, which reduces maintenance over many decades in service."
Debra S. Katz, a lawyer for Salehpour, told the Times that the engineer raised safety concerns with the company but was ignored and sidelined. She said he was transferred to work on another model, the 777, and found problems with the construction of that plane too.
"This is a culture that prioritizes production of planes and pushes them off the line even when there are serious concerns about the structural integrity of those planes and their production process," Katz said.
In its statement, Boeing said: "We continue to monitor these issues under established regulatory protocols and encourage all employees to speak up when issues arise. Retaliation is strictly prohibited at Boeing."
An FAA statement said: “Voluntary reporting without fear of reprisal is a critical component in aviation safety. We strongly encourage everyone in the aviation industry to share information. We thoroughly investigate all reports."
This article first appeared on NBCNews.com. Read more from NBC News: