Qantas, Southwest step up checks of Boeing 737 NGs after more cracks found

SYDNEY/CHICAGO (Reuters) - Qantas Airways Ltd and Southwest Airlines Co are stepping up checks for structural cracks on Boeing Co 737 NGs after discovering problems with planes that did not require urgent inspections, airline sources said.The cracks are on what is known as the "pickle fork" - a part that attaches the plane's fuselage, or body, to the wing structure.Repairing the cracks requires grounding the airplane and costs an estimated $275,000 per aircraft, according to aviation..