Boeing is under scrutiny over reports of recurring errors on the assembly line for the 787 Dreamliner plane. The errors are believed to have stemmed from a manufacturing process that allows mechanics to self-inspect their work, The Post and Courier reported, citing Boeing workers.

Some of the errors found on the production line included debris in airspeed sensors, rags and bolts in planes, and loose cabin seats, The Post and Courier reported. Tires with cuts in them, untested gears, and malfunctioning hydraulics systems were also spotted by workers, according to the report.

Workers told The Post and Courier that 90% of the aircraft's production was part of the self-inspect program. M ost of the mistakes were caught before the plane's delivery to an airline, according to the report.

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Boeing is under scrutiny over reports of recurring errors on the assembly line for the 787 Dreamliner plane. The errors are believed to have stemmed from a manufacturing process that allows mechanics to self-inspect their work, according to The Post and Courier.

Errors on the production line included debris in airspeed sensors, rags and bolts in planes, and loose cabin seats, The Post and Courier reported. Tires with cuts in them, untested gears, and malfunctioning hydraulics systems were also spotted by workers, the newspaper said.

Workers told The Post and Courier that 90% of the aircraft's production was part of the self-inspect program. Most of the mistakes were caught before the plane's delivery to an airline, according to The Post and Courier report.

"I'm always finding cases where jobs are signed off and the parts aren't installed," a Boeing employee who spoke on the condition of anonymity told the newspaper. "It happens a lot."

"It's an everyday thing — every single day," another Boeing employee said, according to The Post and Courier.

Ernesto Gonzalez-Beltran. Boeing

Employees said that while allowing workers to inspect their own work was quicker for production, it also compromised passenger safety.

The duration of the final assembly process has been slashed by several days, but the drawback is that workers spent more time fixing problems with the 787s before their first test flights.

"Boeing has strict methods which ensure our final products comply with design and regulatory requirements," Boeing spokesman Peter Pedraza told Business Insider in an emailed statement on Monday.

"We are strengthening our approach to quality and putting resources in place to bolster our focus on preventing defects throughout our production system," Pedraza said.

Ernesto Gonzalez-Beltran, Boeing's vice president of quality control, told The Post and Courier, "Where there are consistently stable processes, we believe there is no value added for a second set of eyes."

Gonzalez-Beltran, who has worked as an executive for Toyota and Ford Motor Co., had no experience in the aviation-manufacturing industry before arriving at Boeing and has expanded the self-inspect program, according to The Post and Courier.

Pedraza echoed those sentiments in his statement to Business Insider:

A small fraction of our evolution includes streamlining secondary inspections for processes which are proven to be stable. At the same time we are improving upon the traditional inspection approach with new process controls, new technologies and improved designs that make our work less susceptible to errors. Mechanics performing the actual job will always verify and ensure the work meets certification standards.

Boeing has been under pressure after two deadly crashes on the company's 737 Max planes. Two 737s crashed within a five-month period, killing 346 people. An investigation into the crashes is ongoing.

The company has also faced questions over its business practices, including its pilot-training process and the its close ties to the industry's regulator, the Federal Aviation Administration.