The flight was three miles (14850 feet) off the ground so the decompression and other issues were not catastrophic. The pressure dropped from 14.09 psi to about 11.64 psi. The plane was able to get to below 10,000 feet and then return the airport.

A door plug is used to fill a doorway and held together by 12 stop fittings, which prevent the door plug from becoming dislodged. In this case, the plug was not used for a functional door.

United and Alaska Air Boeing 737 Max 9 planes were grounded by the National Transportation and Safety Board. United Airlines and Alaska Airlines have found loose hardware during inspections of Boeing 737 Max 9 planes. Loose bolts have been found on door plugs of several (at least five) Boeing 737 Max 9 planes during inspections.

Alaska has 65 of the Max 9 planes. United has 79, which makes United the biggest operator of the jet model. Boeing, which has spent years trying to clean up a host of quality defects, while also ramping up aircraft production, including of the 737 Max. The 737 Max is Boeing's best-selling aircraft, with more than 4,000 orders to fill. However, the more common Max 8, which is not affected by the grounding, makes up the majority of those orders.