Boeing will add inspections for its 737-9 fleet after a mid-flight emergency revealed the potential of loose bolts on plugged exit doors for several planes.

Why it matters: The plane model is remaining grounded for the foreseeable future, as the company faces a lawsuit.

• Earlier this month, a door plug blew out of a Boeing 737-9 jet during an Alaska Airlines flight, prompting the door to fly open as the plane approached an altitude of 16,000 feet.

The latest: Boeing is adding inspections throughout its build process to "provide one more layer of scrutiny on top of the thousands of inspections performed today across each 737 airplane, and build on the reviews we have implemented to catch potential non-conformances," the company said on Monday.

• Boeing will also review the work of Spirit AeroSystems, which installed the door plug that malfunctioned on the Alaska Airlines flight.

Zoom out: The company is also opening its factories to airlines, and allow them to inspect its production and quality procedures.

• "Customer representatives will continue to have access to anything they want to see onboard their airplane before delivery," the company said.

Between the lines: The Federal Aviation Administration said on Friday it would increase oversight of Boeing's production and manufacturing.

• The FAA is also investigating Boeing over whether the company failed to ensure that the jets were safe.

Meanwhile, Alaska Airlines said on Saturday that it will "enhance" its oversight of planes manufactured by Boeing by performing additional inspections.

Go deeper: What's going on with Boeing 737 Max 9 planes