Decades-old assumptions about how pilots would behave and a failure to grasp the complexity of a new flight-control system plagued the design certification of Boeing’s 737 MAX, a blue-ribbon panel of experts concluded.

The group issued 10 recommendations, calling on the U.S. Federal Aviation Administration to improve communication with the companies it oversees and to require more rigorous safety assessments.

The panel, appointed by the U.S. Transportation Department after the two fatal 737 MAX crashes that prompted the jet’s grounding, said “reforms must be adopted to help our extremely safe aviation system become even better at identifying and mitigating risk.”

In one recommendation, the panel found Boeing employees deputized by FAA to approve aircraft designs need to be shielded from undue pressure, though it said the overall system should be retained.

The report also found “FAA’s overall certification system to be effective.” It also differed with some victim’s families and reformers when it concluded there was no value to recertifying updated designs like the 737 MAX as if they were completely new.

The findings and recommendations zeroed in on several issues that have been raised by previous reports and panels on how the Maneuvering Characteristics Augmentation System, the flight-control system implicated in both crashes, was approved:

  • The FAA and Boeing need to better assess how pilots will react to complex emergencies, such as when MCAS malfunctioned, repeatedly pushing the planes into dives from which the pilots were unable to recover.
  • The agency should improve its pilot-training standard to raise the level of safety in other nations.
  • The government needs to recruit more experts to the workforce assessing new aircraft designs.

Boeing issued an emailed statement saying safety is the company’s “core value” and it was committed to making improvements.

“We will study these recommendations closely, as we continue to work with government and industry stakeholders to enhance the certification process,” the company said in the statement.