Boeing’s attempts to stem safety concerns faced criticism in U.S. congressional hearings on April 17.

Expert panel member Javier de Luis said Boeing’s safety-first message, adopted after two Boeing 737-8 fatal accidents in 2018 and 2019, does not resonate with front-line workers.

“They hear safety is our number one priority,” said de Luis, an aerospace engineer whose sister was one of the 157 people killed in the second 737-8 accident, Ethiopian Airlines Flight 302. “But what they see is that that’s only true as long as your production milestones are met.”

The hearing was prompted by reports of production shortcuts from Boeing quality engineer Sam Salehpour.

Salehpour testified concerns about Boeing’s assembly processes — forcing fuselage subassemblies together and improperly drilling some fastener holes— which allegedly signal long-term risk to affected structures.

Boeing rejected the allegations.

“Extensive and rigorous testing of the fuselage and heavy maintenance checks of nearly 700 in-service airplanes to date have found zero evidence of airframe fatigue,” Boeing stated. “We are fully confident in the safety and durability” of the 787.

Boeing’s reputation took a significant hit after the January 5 Alaska Airlines 737-9 door plug blowout.

NTSB investigators learned the door plug, normally fixed in place with four bolts, was detached and opened on Boeing’s assembly line to make room for repairs to adjacent rivets. The bolts were apparently never re-installed, and the door slowly worked itself free over several weeks of flights after Alaska put the new aircraft into service.