Boeing is defending the integrity of the fuselages of two of its largest planes, which have drawn criticism from a whistleblower who warns that panels on the exterior of one of the planes could eventually fall apart in flight.
Two Boeing technical managers on Monday went into detail about how panels are put together, especially on the 787 Dreamliner. They suggested that the 787’s carbon composite skin is virtually impervious to metal fatigue that weakens conventional aluminum fuselages.
Their comments during a lengthy media briefing served both as a response to news reports last week about the whistleblower’s allegations and as a preemptive strike before he is set to testify before a congressional panel on Wednesday.
The whistleblower, Boeing engineer Sam Salehpour, said excessive force was applied to fit the panels together on the 787 assembly line, increasing the risk of fatigue or microscopic cracks in the material that could cause it to come apart traps.
Boeing officials described how parts of a fuselage are brought together, shims are added to fill gaps, holes are drilled and cleaned, and fasteners are attached to apply “pull-up force,” which 99% of the time results in margins not greater than . 0.127 millimeters apart – the width of a human hair, they said. In 2019, a gap problem was discovered between two panels, leading to design and installation changes, they said.
Boeing conducted tests that replicated 165,000 flights with no fatigue in the composite structure, said Steve Chisholm, Boeing vice president of structural engineering. The average 787 makes 600 flights a year, he said.
The company said the planes already in use appear to be safe. Chisholm said 671 Dreamliners have undergone the intensive inspections for 6-year-old aircraft and eight have undergone 12-year inspections with no signs of fatigue in the composite skins.
Cracks were found in metal parts, including one above where the wings join the fuselage, and Boeing has established inspection guidelines for those parts, officials said.
The 787 Dreamliner is a twin-aisle aircraft that has been commonly used on international flights since its debut in 2011. The composite material makes the aircraft lighter, which contributes to better fuel efficiency.
A series of battery fires briefly grounded the planes. Deliveries of the plane have been halted at times amid questions about gaps between fuselage panels being larger than Boeing standards allowed, the use of unapproved titanium parts from a supplier in Italy and defects in a pressure bulkhead.
The Federal Aviation Administration must inspect and approve every 787 that rolls off the assembly line before it can be flown to an airline customer.
Whistleblower Salehpour claims that after he raised concerns about the 787’s safety, Boeing moved him to an older widebody plane, the 777. He told the Seattle Times that he saw workers jumping on fuselage panels to align them get, which Boeing disputes. .
The New York Times reported that the FAA is investigating Salehpour’s claims. While the FAA would not comment specifically on Salehpour, it said it investigates all safety reports.
Boeing says it has “complete confidence” in both aircraft.
Salehpour is the latest in a series of Boeing whistleblowers to come forward, often claiming retaliation for raising safety concerns. The company said it encourages employees to talk about problems.
Lisa Fahl, the vice president of engineering for Boeing aircraft programs, said employee reports have “exploded” — with as many reports in January and February as in all of 2023 — “and that’s what we want.”