737 Max: US Senate committee criticises oversight of Boeing
A powerful US Senate committee has warned of serious weaknesses in the way new aircraft have been built by Boeing.
It also criticised how the company's aircraft were certified as safe to fly by the regulator, the Federal Aviation Administration (FAA).
The Senate Committee on Commerce, Science and Transportation report was based on the testimony of seven whistleblowers from the industry.
It came in response to two Boeing 737 Max crashes, which killed 346 people.
Boeing said it was reviewing the report: "Boeing teammates are encouraged to speak up whenever they have safety or quality concerns," the planemaker said.
It also said that many issues in the report "have been previously publicized, and Boeing has worked to address them with oversight" by the FAA.
On Monday, the FAA said it "takes all whistleblower allegations seriously and does not tolerate retaliation against those who raise safety concerns."
Whistleblowers raised serious concerns, but were ignored or sidelined, and lives were put at risk. It is a familiar refrain. But now, some of those whistleblowers have been listened to.
The Senate report is based on testimony from seven named individuals, all of them highly qualified. One still works at Boeing, while another remains at the FAA.
They include the likes of Ed Pierson, a former senior manager on the 737 Max programme; Martin Bickeboeller, who played a leading role in the development of the 787; and former FAA safety engineer Joe Jacobsen.
Their testimony paints a disturbing picture of lax production standards and deeply inadequate safety oversight, at a time when the industry has been facing new challenges because of the increasing complexity of aircraft.
Both the FAA and Boeing insist they have worked to address the weaknesses highlighted in the report. But two of the whistleblowers on the list recently told the BBC they still had concerns about the safety of the 737 Max.
Risk of 'catastrophic failure'
The 97-page Aviation Safety Whistleblower Report highlighted allegations that the FAA's safety certification process "suffers from undue pressure on line engineers and production staff".
It also described conflicts of interest, where for example the same engineer had been responsible for preparing equipment for official tests, as well as carrying out those same tests.
It claimed that engineers with specific technical expertise were ignored or sidelined during the development of both Boeing's 737 Max and of the 787 Dreamliner.
In one case, it says, an FAA engineer warned his superiors that the 787 faced a risk of "catastrophic failure due to uncontrolled fire" due to the way its batteries were installed. In 2013, the 787 was grounded due to battery fires.
The report also includes claims by whistleblowers that there are gaps in the FAA's processes, that "have resulted in aircraft designs that do not meet the most recent airworthiness standards".
It said this allowed the 737 Max to be approved to fly while equipped with software - later implicated in both crashes - that "did not receive proper scrutiny".
Flaws in the aircraft's systems were "creatively hidden or outright withheld" from the FAA during the certification process, the report said.
The report went on to say that the FAA had failed to provide enough safety engineers to oversee the much-criticised "Organization Designation Authorization" programme, under which Boeing itself was responsible for carrying out a significant amount of safety certification work on its own products, on behalf of the regulator.
Critics have described this process as being like Boeing "marking its own homework".
The committee report also draws on testimony that suggests the FAA has prioritised efficiencies, by delegating increasing amounts of work - and its safety oversight has been eroded as a result.
The document pointed out that in recent years the regulator certified two aircraft - the 787 and the 737 Max - which were later grounded for safety reasons.
In the case of the 737 Max this led to the loss of hundreds of lives and is estimated to have cost Boeing more than $20bn (£15.2bn).
In January, Boeing agreed to a deferred prosecution agreement with the US Justice Department, including $2.5bn in fines and compensation linked to the 737 Max crashes.