NTSB begins hearings in Alaska Airlines door plug blow out investigation

The NTSB is conducting a two-day hearing to investigate the door plug blowout on an Alaska flight. The focus is on understanding the events leading up to the incident, not on Boeing's broader controversies. The hearing revealed factory stress and poor communication between Boeing and Spirit Aero Systems. Preliminary findings indicate missing documentation for work done on the door plug. The hearing will continue, but a probable cause won't be determined for at least a year.

What is the main focus of the NTSB hearing mentioned in the text?

What did Jennifer Homedy emphasize regarding the investigation?

What were the conditions like for Boeing workers according to the documents released?

What issue was identified regarding the documentation of the door plug work?

What is the expected timeline for determining a probable cause in this investigation?