A Boeing engineer said on Monday that extensive testing had shown “zero” evidence of fatigue stress in the composite materials that make up its 787 jet, two days before a whistleblower is due to testify to the US Congress about what he has described as “catastrophic safety risks” in its manufacturing.
Steve Chisolm, Boeing’s chief engineer for mechanical and structural engineering, told reporters that the carbon fibre composites used to build the jet have successfully endured stress testing that far exceeds normal operating conditions for a commercial jetliner.
“The average 787 accrues about 600 flights a year,” he said at an event at the company’s plant in South Carolina that builds the 787. “We did 165,000 [flight] cycles . . . There were zero findings of fatigue in the composites.”
Boeing is trying to reassure airlines and the flying public in the wake of allegations last week from a longtime engineer at the manufacturer that it was taking “shortcuts” in building the wide-body jet that could cause it to break apart. The US Federal Aviation Administration is investigating his claims.
The engineer, Sam Salehpour, also said Boeing retaliated against him when he floated his concerns by moving him to the 777 programme, where he said there were separate problems with misaligned fuselage sections.
Salehpour will speak on Wednesday at a hearing held by the Senate Permanent Subcommittee on Investigations. Separately, the Senate Commerce, Science and Transportation Committee will hear testimony the same day from three aviation experts who sat on the panel that criticised Boeing’s safety culture.
Last week the company called Salehpour’s allegations about the structural integrity of the 787 “inaccurate”. The issues he raised “have been subject to rigorous engineering examination under FAA oversight”, Boeing said, and the company found the aircraft was safe to fly over decades.
Retaliation, it added, is “strictly prohibited”.
Boeing is facing scrutiny from regulators and the US Department of Justice after a door panel blew out mid-flight on a 737 Max in January. A preliminary report by the National Transportation Safety Board found that four bolts meant to secure the door to the fuselage were missing.
An audit by the FAA found “multiple instances” where the company allegedly failed to meet manufacturing quality control requirements. The regulator has limited the number of 737 Maxes Boeing can build per month to 38 and given the company until the end of May to submit a plan to improve quality.
Salehpour’s critique stems from gaps Boeing found in the 787 four years ago at joints between fuselage sections. Boeing had fitted the gaps with improperly sized slivers of material, known as shims, and the company halted 787 deliveries for the bulk of two years as it worked to correct the problem. The FAA permitted the plane maker to resume deliveries in August 2022.
But the aerospace engineer said the company was using too much force when it joined together fuselage sections, squeezing the sections too tightly and masking when a shim was necessary. That could make the sections move against each other, leading to fatigue that could “ultimately cause a premature fatigue failure without any warning”, Salehpour said in a January 19 letter to Michael Whitaker, head of the FAA.