United Airlines is finding loose fitting mounting bolts for the mid aft plug door 737-9 : r/boeing

Panel on Boeing Plane May Not Have Been Properly Attached, Agency Says - The New York Times

Update on B737 MAX 9 - Operators and Regulators Response

United finds loose bolts on 737 Max 9 planes in wake of Alaska Airlines door plug incident - ABC News

Alaska Airlines 737-900 MAX loses a door in-flight out of PDX - Page 74 - PPRuNe Forums

Gosh, The Boeing 737 MAX Is A Mess - One Mile at a Time

Section of MAX 9 Blows Out During Ascent (AS 1282 PDX-ONT) - Page 28 - FlyerTalk Forums

Alaska, United find loose hardware during inspection of 737 MAX 9s

Gosh, The Boeing 737 MAX Is A Mess - One Mile at a Time

United Airlines finds loose bolts, other issues on a key part of grounded Boeing 737 Max 9 jetliners