The airline , along with its parent company , Northwest Airlines Corporation and subsidiaries , operated under Chapter 11 bankruptcy protection which , in the United States , allows continued operation during the reorganization effort , not stopping flights as in the case in some countries . The airline , along with its then-parent company , Northwest Airlines Corporation and subsidiaries , operated under Chapter 11 bankruptcy protection which , in the United States , allows continued operation during the reorganization effort , not cessation of flights as in the case in some countries .