For most of his career at Spirit AeroSystems, Santiago Paredes worked at the end of the line. It was his job to catch production errors before the fuselage left the factory in Wichita, and Paredes caught a lot of them.

“It’s poor quality. Poor quality of work, just plain and simple,” he says, flipping through photos on his phone of the serious mistakes that he flagged during his dozen years as a quality inspector at Spirit.

Boeing is trying to rebuild its battered reputation for quality after a door plug blowout on a 737 Max in midair last January. The troubled plane-maker is in talks to buy Spirit AeroSystems, a key supplier that makes the fuselage for Boeing in Wichita, Kan.

“They say the correct things like they've always said,” said whistleblower Santiago Paredes. “But I know how they really are.” A clash with management

Paredes says he brought his concerns to his managers repeatedly. But they were more worried about getting fuselages out of the factory faster to keep up with Boeing’s backlog.

“They were upset for me finding defects,” Paredes said. “It was never the people that created the defects fault. It was my fault for finding it.”

It got to the point, Paredes says, that a manager ordered him in writing to essentially undercount the number of mistakes.

“They wanted me to basically falsify the documentation on the amount of defects that were being found,” Paredes said. “They were telling me to lie.”