Staff at Boeing are still reluctant to speak up about safety problems, even after a door panel on one of its jets recently blew out mid-flight and hundreds of lives were lost in two earlier planes crashes, according to an experts’ report commissioned by the United States Federal Aviation Administration (FAA).

The report, published in February, did not comment on these particular incidents. But it said that, while Boeing had taken steps to improve its safety culture, staff were still hesitant about voicing concerns because they feared retaliation. It noted that the jet maker’s “speak up” programme, which allows employees to report safety problems confidentially, suffers from workers not believing their anonymity will be protected.