U.S. regulators have issued a scathing assessment of Boeing’s safety culture, putting further pressure on the company as it contends with the fallout from a near-catastrophic accident at the start of the year.

The planemaker was faulted for ineffective procedures and a breakdown in communications between senior management and other members of staff, a panel of experts convened by the Federal Aviation Administration said in a report released Monday. Constant changes to complex procedures and trainings led to confusion, while other shortcomings hindered the average employee’s understanding of their role in how Boeing manages safety, according to the report, which was mandated by U.S. lawmakers.

"I really hope this is a wake-up call to the Boeing Company,” said Rich Plunkett, a member of the expert review panel and director of strategic development for the union that represents Boeing’s engineers.