US Civil Aviation Authority (FAA) controls in the production process of the passenger aircraft 737 Max of Boeingfollowing an incident in which a frame detached during Alaska Airlines’ initial flight in January, revealed “dozens” of problems, with “33 failures in 89 tests,” the New York Times reported Monday.

Boeing’s third-party supplier, Spirit AeroSystems, which makes the fuselage of these passenger jets, passed just six of the thirteen FAA “tests,” according to the report, which cited an internal presentation about the process.

Neither the FAA, Boeing nor Spirit immediately responded when contacted by Reuters for comment on the Times report.

earlier yesterday, US Secretary of Transportation Pete Buttigieg dHe said he expects the automaker, one of the world’s two largest, to cooperate fully with the Justice Department and National Transportation Safety Board (NTSB) investigations into the Jan. 5 incident, which could prove catastrophic if the aircraft was at a higher altitude.

At the same time, Michael Whitaker of the FAA said that his agency and Boeing hope to agree on the conditions that will have to be met by the manufacturer in order to increase the production of the Max in the coming weeks.

Last week, the FAA announced that it had found issues of Boeing’s “non-compliance” with rules in “manufacturing process control”, “parts handling and storage”, and “product” quality control.

Boeing probably passed the most serious crisis in historys when two aircraft of this type crashed, in Indonesia and Ethiopia, with no survivors out of a total of 346 on board, in late 2018 and early 2019; the cause was mainly a problem with the data-driven MCAS stall avoidance software only one sensor, while the pilots were not trained for it. The entire Max fleet was grounded from March 2019 to November 2020. The issue was resolved and the aircraft of the type eventually returned to the airwaves, but the Max continues to experience problems.