Boeing is 'not cooperating' with NTSB investigation into mid-air blowout on Alaska Airlines flight

The head of the National Transportation Safety Board has accused Boeing of failing to provide some key records sought in its ongoing investigation into the Alaska Airlines 737 Max mid-air cabin door emergency.

NTSB Chair Jennifer Homendy said investigators have sought the names of the 25 people who work on door plugs at a Boeing facility in Renton, Washington, but have not received them from Boeing. 

'It is absurd that two months later we don't have it,' Homendy said at a Senate Commerce Committee hearing on Wednesday.

Boeing insisted that it had initially provided the NTSB with some of the names of Boeing employees, including door specialists it believed would have relevant information.

'We have now provided the full list of individuals on the 737 door team, in response to a recent request,' the planemaker said, adding, 'if the door plug removal was undocumented there would be no documentation to share.' 

NTSB Chair Jennifer Homendy said investigators have sought the names of the 25 people who work on door plugs at a Boeing facility in Renton, Washington, but have not received them

Bolts appear to be missing from the door plug that blew out of a Boeing 737 MAX during an Alaska Airlines flight on January 5

'We will continue to cooperate fully and transparently with the NTSB´s investigation,' the Boeing statement added.

Earlier on Wednesday, Homendy said she was frustrated.

'It's not for lack of trying,' she said, adding that the information being sought includes the precise shift that worked on the improperly installed door plug in September. 

The agency also seeks documentation related to opening and closing of the door plug and removal of key bolts that were missing.

Homendy said the NTSB has requested documentation related to the door plug 'numerous times over the past few months.'

Separately, she told Reuters the NTSB plans to hold a multiple-day investigative hearing into the MAX 9, likely in late summer, which will include testimony from Boeing personnel and fuselage manufacturer Spirit AeroSystems.

Homendy confirmed that inspections of all other MAX 9 planes in service found no other missing bolts.

The planemaker has scrambled to explain and strengthen safety procedures since the January mid-air incident that led to the FAA grounding the MAX 9 for several weeks. 

The company has been the subject of increased scrutiny from regulators and big air carriers concerned about the quality of jet production.

The door plug was recovered from the back yard of a home after it blew out on January 5

Homendy said investigators began interviews at Boeing's Renton plant on Sunday and that they will continue all week. At present, the NTSB does not know which employees removed the bolts and failed to reinstall them, she said.

'The NTSB needs to interview the employees,' she said. 'We are not about blame at the NTSB. This is the only way we ensure safety is to find out what happened, what was done, what was not done, what policies are in place.'

Homendy said she was not suggesting any malfeasance on Boeing's part.

Senator Ted Cruz, the top Republican on the Commerce Committee, called it 'utterly unacceptable' that the NTSB was not receiving full cooperation from Boeing.

Homendy also confirmed that the MAX 9 door plug had moved during prior flights, citing markings on the door. 

There were 154 prior flights by the Alaska Airlines Boeing 737 MAX 9 before the January 5 mid-air emergency. 

'There were very small movements until it eventually came out,' Homendy said, adding that testing showed 'you could see a bit of a gap towards the end' but that it was not clear how noticeable it was.

The Federal Aviation Administration this week said its 737 MAX production audit into Boeing and Spirit AeroSystems found multiple instances where the companies allegedly failed to comply with manufacturing quality control requirements. 

The FAA has given Boeing 90 days to come up with a quality improvement plan.