(Reuters) -Boeing mentioned on Monday it has not discovered fatigue cracks on in-service 787 jets which have gone by way of heavy upkeep, because the planemaker defended the twin-aisle plane program forward of a U.S. Senate listening to on Wednesday.

Final week, a Boeing (NYSE:) whistleblower alleged that the corporate dismissed security issues concerning the meeting of its 787 and 777 jets that fly worldwide routes. The whistleblower, Boeing high quality engineer Sam Salehpour, is ready to testify within the Senate listening to on the corporate’s security tradition.

Salehpour has claimed that Boeing didn’t adequately shim, or use a skinny piece of fabric to fill tiny gaps in a manufactured product, an omission that would trigger untimely fatigue failure over time in some areas of the Boeing 787 Dreamliner.

His claims, that are being investigated by the U.S. Federal Aviation Administration (FAA), embrace remarks that he noticed staff “leaping on the items of the airplane to get them to align.”

Boeing has been grappling with a full-blown security disaster that has undermined its repute following a Jan. 5 mid-air panel blowout on a 737 MAX single-aisle airplane.

On a name with reporters on Monday, two senior Boeing officers mentioned there have been zero airframe fatigue findings among the many close to 700 in-service Dreamliner jets which have undertaken heavy upkeep inspections after six years and 12 years.

“All these outcomes have been shared with the FAA,” mentioned Steve Chisholm, Boeing’s chief engineer, mechanical and structural engineering.

Boeing halted deliveries of the 787 widebody jet for greater than a 12 months till August 2022 because the FAA investigated high quality issues and manufacturing flaws.

In 2021, Boeing mentioned some 787 airplanes had shims that weren’t the correct dimension and a few plane had areas that didn’t meet skin-flatness specs.

The 787, which was launched in 2004, had a specification of five-thousandths of an inch hole allowance inside a five-inch space, or “the thickness of a human hair,” mentioned Lisa Fahl, vp of Boeing Industrial Airplanes airplane packages engineering.

She mentioned stories of staff leaping on airplane elements have been “not a part of our course of.”

Salehpour’s lawyer, Debra Katz, mentioned in an emailed assertion that her shopper tried for years to see knowledge that may handle his issues concerning the security of gaps within the 787.

“Any knowledge supplied by Boeing must be validated by unbiased specialists and the FAA earlier than it’s taken at face worth,” Katz mentioned.