needed to know as the technology became more complex. >> reporter: the report is scathing, finding an inadequate number of specialists were involved in the certification process. some faa engineers had limited experience and knowledge of key technical aspects of the plane, and it resulted in an inability of the faa to provide an independent assessment of boeing's activities. >> i welcome the scrutiny. >> reporter: the new faa chief talked to us before the report's release. is it possible that too much authority was delegated to boeing? >> it's possible we will have to see. i haven't made a decision on that yet. >> reporter: congress long ago ordered the faa to work with manufacturers to expedite certifications tonight boeing tells nbc news it's committed to working with the faa in reviewing the recommendations. also today united airlines joined american and southwest in taking the max out of its fleet until january at the earliest that's assuming the faa reapproves the plane for flight that means no u.s.